Related
In javascript I can have, for example,
var a = 1;
while (a < 10) a++;
if (a === 10) a = 1;
So there are situations where braces are not required (though I usually put them in for clarity and to stop jshint from bothering me about their lack.)
Curiously (to me anyway) function doesn't work the same. I do
function bar(a) { return a + 1; }
but can't do
function foo(a) return bar(a);
What is so different about function that it can't behave like if and while etc?
Eliminating braces for single line statements/expressions is a common pattern across many languages.
It's just syntactic sugar for the (lazy :)) programmer.
If you have multiple statements within the if or while, you would still have to write the {} around them.
I would personally suggest always doing so because forgetting {} could lead to non-obvious bugs sometimes:
let i = 0;
if (i > 0)
i++;
console.log('this still happens');
Addition of arrow functions in ES6 allows this same behavior with functions:
Your function:
function bar(a) { return a + 1; }
Could be written without {} because it has a single expression:
const bar = a => a + 1;
But omitting {} for multiple operations would again be a bug:
let x = x => x + 1; console.log('this still happens');
You could get away with using the , operator to chain expressions:
let i = 0;
if (i > 0)
i++, // <-- notice the comma
console.log('now this does not happen');
But that arguably makes for far less readable code.
Bottom line is, using {} by default is a good choice in most cases.
It's all about syntax.
In scheme, a function maybe looks like this:
(define (square x)
(* x x))
In python, a function maybe looks like this:
def square(x):
return x * x
So, JavaScript Function Declaration Statement is:
function name_this_is_function_header(...parameters) {
// and this is function body
// statements
}
It must include a body which notation is { } . (though, ES6 add a syntax sugar for arrow function, () => { } , you can omit { } if only one statement in it, anyway)
function is a token, ( ) is a pair of tokens, { } also a pair of tokens, compiler or interpreter treat them all as a whole abstraction named JavaScript function.
JavaScript borrowed a lot syntax from Java, Java did the same thing to C++, C++ did the same thing to C ... , that's why.
For statement, such as if and while, it's syntax:
if (condition) one-statement;
while (condition) one-statement;
So, it's all about statement, statement could be single, could be compound.
Single statement don't need { }, compound statement is just several single statements included by { } tokens or notations. If you need several statements after true, you must use compound statement as a whole.
It's not about something mysterious, It's just how do you write it to express.
In the following recursive function, I expect the function to return "arrived" at the end but instead, it returns undefined. Isn't that when the excution goes in the if block the code should return? Appreciate your comments on this.
function myFun(i){
if(i===0){return ('arrived');}
i = i - 1;
myFun(i);
}
If I change the code as follows then it'll return "arrived" but still don't know why the above doesn't return "arrived".
function myFun(i){
if(i===0){return ('arrived');}
i = i - 1;
return myFun(i);
}
The first function does not return a value because all code paths must return a value. And after the first line, there is no return statement. It only returns a value when called with 0 as parameter.
Recursion is a functional heritage and so writing your program in a functional style will yield the best results.
This means avoiding things like
imperative style statements for, if, switch, etc that do not return a value
mutation or variable reassignments like i = i + 1
const myFun = i =>
i === 0
? "arrived"
: myFun (i - 1)
console.log (myFun (10))
// "arrived"
Notice expressions, unlike statements, evaluate to a value. We made the following changes
function statement function myFun (i) { ... } replaced with a function expression myFun (i) => ...
if statement replaced with ternary expression, eg condition ? ifTrue : ifFalse
variable assignment statement i = i - 1; myFun(i) replaced with expression myFun(i - 1)
Note, the return statement itself is a side effect and has little use in a functional JavaScript program.
Going along with the other answer here, all code paths must return a value! An advantage to writing your program in a functional style means you can't write a function that doesn't return a value, nor can you write a conditional with only one branch.
TL;DR: use functional style and your problem automatically vanishes
I read this question about the "comma operator" in expressions (,) and the MDN docs about it, but I can't think of a scenario where it is useful.
So, when is the comma operator useful?
The following is probably not very useful as you don't write it yourself, but a minifier can shrink code using the comma operator. For example:
if(x){foo();return bar()}else{return 1}
would become:
return x?(foo(),bar()):1
The ? : operator can be used now, since the comma operator (to a certain extent) allows for two statements to be written as one statement.
This is useful in that it allows for some neat compression (39 -> 24 bytes here).
I'd like to stress the fact that the comma in var a, b is not the comma operator because it doesn't exist within an expression. The comma has a special meaning in var statements. a, b in an expression would be referring to the two variables and evaluate to b, which is not the case for var a, b.
The comma operator allows you to put multiple expressions in a place where one expression is expected. The resulting value of multiple expressions separate by a comma will be the value of the last comma separated expression.
I don't personally use it very often because there aren't that many situations where more than one expression is expected and there isn't a less confusing way to write the code than using the comma operator. One interesting possibility is at the end of a for loop when you want more than one variable to be incremented:
// j is initialized to some other value
// as the for loop executes both i and j are incremented
// because the comma operator allows two statements to be put in place of one
for (var i = 0; i < items.len; i++, j++) {
// loop code here that operates on items[i]
// and sometimes uses j to access a different array
}
Here you see that i++, j++ can be put in a place where one expression is allowed. In this particular case, the multiple expressions are used for side affects so it does not matter that the compound expressions takes on the value of the last one, but there are other cases where that might actually matter.
The Comma Operator is frequently useful when writing functional code in Javascript.
Consider this code I wrote for a SPA a while back which had something like the following
const actions = _.chain(options)
.pairs() // 1
.filter(selectActions) // 2
.map(createActionPromise) // 3
.reduce((state, pair) => (state[pair[0]] = pair[1], state), {}) // 4
.value();
This was a fairly complex, but real-world scenario. Bear with me while I explain what is happening, and in the process make the case for the Comma Operator.
This uses Underscore's chaining to
Take apart all of the options passed to this function using pairs
which will turn { a: 1, b: 2} into [['a', 1], ['b', 2]]
This array of property pairs is filtered by which ones are deemed to be 'actions' in the system.
Then the second index in the array is replaced with a function that returns a promise representing that action (using map)
Finally the call to reduce will merge each "property array" (['a', 1]) back into a final object.
The end result is a transformed version of the options argument, which contains only the appropriate keys and whose values are consumable by the calling function.
Looking at just
.reduce((state, pair) => (state[pair[0]] = pair[1], state), {})
You can see the reduce function starts with an empty state object, state, and for each pair representing a key and value, the function returns the same state object after adding a property to the object corresponding to the key/value pair. Because of ECMAScript 2015's arrow function syntax, the function body is an expression, and as a result, the Comma Operator allows a concise and useful "iteratee" function.
Personally I have come across numerous cases while writing Javascript in a more functional style with ECMAScript 2015 + Arrow Functions. Having said that, before encountering arrow functions (such as at the time of the writing of the question), I'd never used the comma operator in any deliberate way.
Another use for the comma operator is to hide results you don't care about in the repl or console, purely as a convenience.
For example, if you evaluate myVariable = aWholeLotOfText in the repl or console, it will print all the data you just assigned. This might be pages and pages, and if you'd prefer not to see it, you can instead evaluate myVariable = aWholeLotOfText, 'done', and the repl/console will just print 'done'.
Oriel correctly points out† that customized toString() or get() functions might even make this useful.
Comma operator is not specific to JavaScript, it is available in other languages like C and C++. As a binary operator this is useful when the first operand, which is generally an expression, has desired side effect required by second operand. One example from wikipedia:
i = a += 2, a + b;
Obviously you can write two different lines of codes, but using comma is another option and sometimes more readable.
I'd disagree with Flanagan, and say, that comma is really useful and allows to write more readable and elegant code, especially when you know what you're doing:
Here's the greatly detailed article on comma usage:
Several examples from out from there for the proof of demonstration:
function renderCurve() {
for(var a = 1, b = 10; a*b; a++, b--) {
console.log(new Array(a*b).join('*'));
}
}
A fibonacci generator:
for (
var i=2, r=[0,1];
i<15;
r.push(r[i-1] + r[i-2]), i++
);
// 0,1,1,2,3,5,8,13,21,34,55,89,144,233,377
Find first parent element, analogue of jQuery .parent() function:
function firstAncestor(el, tagName) {
while(el = el.parentNode, el && (el.tagName != tagName.toUpperCase()));
return el;
}
//element in http://ecma262-5.com/ELS5_HTML.htm
var a = $('Section_15.1.1.2');
firstAncestor(a, 'div'); //<div class="page">
I haven't found practical use of it other than that but here is one scenario in which James Padolsey nicely uses this technique for IE detection in a while loop:
var ie = (function(){
var undef,
v = 3,
div = document.createElement('div'),
all = div.getElementsByTagName('i');
while ( // <-- notice no while body here
div.innerHTML = '<!--[if gt IE ' + (++v) + ']><i></i><![endif]-->',
all[0]
);
return v > 4 ? v : undef;
}());
These two lines must to execute :
div.innerHTML = '<!--[if gt IE ' + (++v) + ']><i></i><![endif]-->',
all[0]
And inside comma operator, both are evaluated though one could have made them separate statements somehow.
There is something "odd" that can be done in JavaScript calling a function indirectly by using the comma operator.
There is a long description here:
Indirect function call in JavaScript
By using this syntax:
(function() {
"use strict";
var global = (function () { return this || (1,eval)("this"); })();
console.log('Global === window should be true: ', global === window);
var not_global = (function () { return this })();
console.log('not_global === window should be false: ', not_global === window);
}());
You can get access to the global variable because eval works differently when called directly vs called indirectly.
I've found the comma operator most useful when writing helpers like this.
const stopPropagation = event => (event.stopPropagation(), event);
const preventDefault = event => (event.preventDefault(), event);
const both = compose(stopPropagation, preventDefault);
You could replace the comma with either an || or &&, but then you'd need to know what the function returns.
More important than that, the comma separator communicates intent -- the code doesn't care what the left-operand evaluates to, whereas the alternatives may have another reason for being there. This in turn makes it easier to understand and refactor. If the function return type ever changes, the code above would not be affected.
Naturally you can achieve the same thing in other ways, but not as succinctly. If || and && found a place in common usage, so too can the comma operator.
One typical case I end up using it is during optional argument parsing. I think it makes it both more readable and more concise so that the argument parsing doesn't dominate the function body.
/**
* #param {string} [str]
* #param {object} [obj]
* #param {Date} [date]
*/
function f(str, obj, date) {
// handle optional arguments
if (typeof str !== "string") date = obj, obj = str, str = "default";
if (obj instanceof Date) date = obj, obj = {};
if (!(date instanceof Date)) date = new Date();
// ...
}
Let's say you have an array:
arr = [];
When you push onto that array, you are rarely interested in push's return value, namely the new length of the array, but rather the array itself:
arr.push('foo') // ['foo'] seems more interesting than 1
Using the comma operator, we can push onto the array, specify the array as the last operand to comma, and then use the result -- the array itself -- for a subsequent array method call, a sort of chaining:
(arr.push('bar'), arr.push('baz'), arr).sort(); // [ 'bar', 'baz', 'foo' ]
It saves you from using return in nested conditionals and it's very handy especially with the ternary operator. Such as;
function insert(v){
return this.node > v ? this.left.size < this.right.size ? ( this.left.insert(v)
, this
)
: ( this.left.insert(this.node)
, this.node = this.right.popmin()
, this.insert(v)
, this
)
: this.left.size < this.right.size ? ( this.right.insert(this.node)
, this.node = this.left.popmax()
, this.insert(v)
, this
)
: ( this.right.insert(v)
, this
)
}
I just came across this today looking at the proposals for pipeline operator proposal and partial application...
(https://github.com/tc39/proposal-pipeline-operator
(https://github.com/tc39/proposal-partial-application#hack-style-pipelines)
Also, Hack-style pipelines are already feasible without introducing new syntax today:
let $; // Hack-style topic variable
let result = (
$= books,
$= filter($, _ => _.title = "..."),
$= map($, _ => _.author),
$);
The use of comma expressions here can kind of fake the pipeline operator that isn't in the language yet.
Eliminating the space between $= simulates the feeling of a proper pipe token, |>. Note that the "topic" variable, $, can be anything here and that it's just shorthand for repeatedly overwriting the variable. So something more akin to ...
// blocking inside an IIFE
let result = (() => {
let $;
$ = books;
$ = filter($, _ => _.title = "..."),
$ = map($, _ => _.author),
return $;
})()
The "comma" version successfully cuts out some of the noise, getting you closer to what the proposal would be:
let result = books
|> filter($, _ => _.title = "..."
|> map($, _ => _.author)
Here's another example using it to compose functions:
const double = (x) => 2 * x;
const add = (x, y) => x + y;
const boundScore = (min, max, score) => Math.max(min, Math.min(max, score));
const calculateScore = ($) => (
$= double($),
$= add($, 20),
$= boundScore(0, 100, $),
(console.log($), $)
)
const score = calculateScore(28)
The comma operator (,) evaluates each of its operands (from left to right) and returns the value of the last operand. This lets you create a compound expression in which multiple expressions are evaluated, with the compound expression's final value being the value of the rightmost of its member expressions. This is commonly used to provide multiple parameters to a for loop.
let x = 1;
x = (x++, x);
console.log(x);
// expected output: 2
x = (2, 3);
console.log(x);
// expected output: 3
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Comma_Operator
Another area where comma operator can be used is Code Obfuscation.
Let's say a developper writes some code like this:
var foo = 'bar';
Now, she decides to obfuscate the code. The tool used may changed the code like this:
var Z0b=(45,87)>(195,3)?'bar':(54,65)>(1,0)?'':'baz';// Z0b == 'bar'
Demo: http://jsfiddle.net/uvDuE/
I'd like to concatenate an if statement like so:
policeRecord = "Hi" + (if (x < crimes.length) {", ";});
I know that you can do it using a ternary:
policeRecord = "Hi" + ((x < crimes.length) ? ", " : "");
But can you do it with a full if statement?
if is a statement. Statements cannot be used as part of an expression.
Typically expressions consist of operators and sub-expressions and create values. Statements don't belong in any of these categories, they are not expressions and not operators.
For more technical information, have a look at the ECMAScript specification: http://es5.github.com/.
No, that is invalid JavaScript syntax so you cannot do it.
I'm not sure why you would want to do it either because I actually thing it causes a loss of clarity (there's a lot of jumble of symbols there).
If you wanted to do some sort of fancy one-liner to confuse people without using the ternary operator, you could do array/string manipulation based on element length:
policeRecord = "Hi" + (new Array(+(x < crimes.length) + 1)).join(', ');
if is a statement and doesn't return a value, whereas ? is an operator.
In the case of function it's notable, that there is a function statement and a function operator, so you can do
function () { } // function statement
and you can also do
var fn = function () { }; // function operator
Short answer: You can't replace or interchange if and ?. You may create a function that does it, but running through a function has not the performance of native expressions.
You can also create a function à la SQL's COALESCE (but checking for true instead of NULL):
function iftrue(checkThis, returnIfTrue, returnIfFalse) {
if(checkThis) {
return returnIfTrue;
}
return returnIfFalse;
}
policeRecord = "Hi" + iftrue(1 < crimes.length, ", ", "");
Not sure how much better that would be, though.
I read this question about the "comma operator" in expressions (,) and the MDN docs about it, but I can't think of a scenario where it is useful.
So, when is the comma operator useful?
The following is probably not very useful as you don't write it yourself, but a minifier can shrink code using the comma operator. For example:
if(x){foo();return bar()}else{return 1}
would become:
return x?(foo(),bar()):1
The ? : operator can be used now, since the comma operator (to a certain extent) allows for two statements to be written as one statement.
This is useful in that it allows for some neat compression (39 -> 24 bytes here).
I'd like to stress the fact that the comma in var a, b is not the comma operator because it doesn't exist within an expression. The comma has a special meaning in var statements. a, b in an expression would be referring to the two variables and evaluate to b, which is not the case for var a, b.
The comma operator allows you to put multiple expressions in a place where one expression is expected. The resulting value of multiple expressions separate by a comma will be the value of the last comma separated expression.
I don't personally use it very often because there aren't that many situations where more than one expression is expected and there isn't a less confusing way to write the code than using the comma operator. One interesting possibility is at the end of a for loop when you want more than one variable to be incremented:
// j is initialized to some other value
// as the for loop executes both i and j are incremented
// because the comma operator allows two statements to be put in place of one
for (var i = 0; i < items.len; i++, j++) {
// loop code here that operates on items[i]
// and sometimes uses j to access a different array
}
Here you see that i++, j++ can be put in a place where one expression is allowed. In this particular case, the multiple expressions are used for side affects so it does not matter that the compound expressions takes on the value of the last one, but there are other cases where that might actually matter.
The Comma Operator is frequently useful when writing functional code in Javascript.
Consider this code I wrote for a SPA a while back which had something like the following
const actions = _.chain(options)
.pairs() // 1
.filter(selectActions) // 2
.map(createActionPromise) // 3
.reduce((state, pair) => (state[pair[0]] = pair[1], state), {}) // 4
.value();
This was a fairly complex, but real-world scenario. Bear with me while I explain what is happening, and in the process make the case for the Comma Operator.
This uses Underscore's chaining to
Take apart all of the options passed to this function using pairs
which will turn { a: 1, b: 2} into [['a', 1], ['b', 2]]
This array of property pairs is filtered by which ones are deemed to be 'actions' in the system.
Then the second index in the array is replaced with a function that returns a promise representing that action (using map)
Finally the call to reduce will merge each "property array" (['a', 1]) back into a final object.
The end result is a transformed version of the options argument, which contains only the appropriate keys and whose values are consumable by the calling function.
Looking at just
.reduce((state, pair) => (state[pair[0]] = pair[1], state), {})
You can see the reduce function starts with an empty state object, state, and for each pair representing a key and value, the function returns the same state object after adding a property to the object corresponding to the key/value pair. Because of ECMAScript 2015's arrow function syntax, the function body is an expression, and as a result, the Comma Operator allows a concise and useful "iteratee" function.
Personally I have come across numerous cases while writing Javascript in a more functional style with ECMAScript 2015 + Arrow Functions. Having said that, before encountering arrow functions (such as at the time of the writing of the question), I'd never used the comma operator in any deliberate way.
Another use for the comma operator is to hide results you don't care about in the repl or console, purely as a convenience.
For example, if you evaluate myVariable = aWholeLotOfText in the repl or console, it will print all the data you just assigned. This might be pages and pages, and if you'd prefer not to see it, you can instead evaluate myVariable = aWholeLotOfText, 'done', and the repl/console will just print 'done'.
Oriel correctly points out† that customized toString() or get() functions might even make this useful.
Comma operator is not specific to JavaScript, it is available in other languages like C and C++. As a binary operator this is useful when the first operand, which is generally an expression, has desired side effect required by second operand. One example from wikipedia:
i = a += 2, a + b;
Obviously you can write two different lines of codes, but using comma is another option and sometimes more readable.
I'd disagree with Flanagan, and say, that comma is really useful and allows to write more readable and elegant code, especially when you know what you're doing:
Here's the greatly detailed article on comma usage:
Several examples from out from there for the proof of demonstration:
function renderCurve() {
for(var a = 1, b = 10; a*b; a++, b--) {
console.log(new Array(a*b).join('*'));
}
}
A fibonacci generator:
for (
var i=2, r=[0,1];
i<15;
r.push(r[i-1] + r[i-2]), i++
);
// 0,1,1,2,3,5,8,13,21,34,55,89,144,233,377
Find first parent element, analogue of jQuery .parent() function:
function firstAncestor(el, tagName) {
while(el = el.parentNode, el && (el.tagName != tagName.toUpperCase()));
return el;
}
//element in http://ecma262-5.com/ELS5_HTML.htm
var a = $('Section_15.1.1.2');
firstAncestor(a, 'div'); //<div class="page">
I haven't found practical use of it other than that but here is one scenario in which James Padolsey nicely uses this technique for IE detection in a while loop:
var ie = (function(){
var undef,
v = 3,
div = document.createElement('div'),
all = div.getElementsByTagName('i');
while ( // <-- notice no while body here
div.innerHTML = '<!--[if gt IE ' + (++v) + ']><i></i><![endif]-->',
all[0]
);
return v > 4 ? v : undef;
}());
These two lines must to execute :
div.innerHTML = '<!--[if gt IE ' + (++v) + ']><i></i><![endif]-->',
all[0]
And inside comma operator, both are evaluated though one could have made them separate statements somehow.
There is something "odd" that can be done in JavaScript calling a function indirectly by using the comma operator.
There is a long description here:
Indirect function call in JavaScript
By using this syntax:
(function() {
"use strict";
var global = (function () { return this || (1,eval)("this"); })();
console.log('Global === window should be true: ', global === window);
var not_global = (function () { return this })();
console.log('not_global === window should be false: ', not_global === window);
}());
You can get access to the global variable because eval works differently when called directly vs called indirectly.
I've found the comma operator most useful when writing helpers like this.
const stopPropagation = event => (event.stopPropagation(), event);
const preventDefault = event => (event.preventDefault(), event);
const both = compose(stopPropagation, preventDefault);
You could replace the comma with either an || or &&, but then you'd need to know what the function returns.
More important than that, the comma separator communicates intent -- the code doesn't care what the left-operand evaluates to, whereas the alternatives may have another reason for being there. This in turn makes it easier to understand and refactor. If the function return type ever changes, the code above would not be affected.
Naturally you can achieve the same thing in other ways, but not as succinctly. If || and && found a place in common usage, so too can the comma operator.
One typical case I end up using it is during optional argument parsing. I think it makes it both more readable and more concise so that the argument parsing doesn't dominate the function body.
/**
* #param {string} [str]
* #param {object} [obj]
* #param {Date} [date]
*/
function f(str, obj, date) {
// handle optional arguments
if (typeof str !== "string") date = obj, obj = str, str = "default";
if (obj instanceof Date) date = obj, obj = {};
if (!(date instanceof Date)) date = new Date();
// ...
}
Let's say you have an array:
arr = [];
When you push onto that array, you are rarely interested in push's return value, namely the new length of the array, but rather the array itself:
arr.push('foo') // ['foo'] seems more interesting than 1
Using the comma operator, we can push onto the array, specify the array as the last operand to comma, and then use the result -- the array itself -- for a subsequent array method call, a sort of chaining:
(arr.push('bar'), arr.push('baz'), arr).sort(); // [ 'bar', 'baz', 'foo' ]
It saves you from using return in nested conditionals and it's very handy especially with the ternary operator. Such as;
function insert(v){
return this.node > v ? this.left.size < this.right.size ? ( this.left.insert(v)
, this
)
: ( this.left.insert(this.node)
, this.node = this.right.popmin()
, this.insert(v)
, this
)
: this.left.size < this.right.size ? ( this.right.insert(this.node)
, this.node = this.left.popmax()
, this.insert(v)
, this
)
: ( this.right.insert(v)
, this
)
}
I just came across this today looking at the proposals for pipeline operator proposal and partial application...
(https://github.com/tc39/proposal-pipeline-operator
(https://github.com/tc39/proposal-partial-application#hack-style-pipelines)
Also, Hack-style pipelines are already feasible without introducing new syntax today:
let $; // Hack-style topic variable
let result = (
$= books,
$= filter($, _ => _.title = "..."),
$= map($, _ => _.author),
$);
The use of comma expressions here can kind of fake the pipeline operator that isn't in the language yet.
Eliminating the space between $= simulates the feeling of a proper pipe token, |>. Note that the "topic" variable, $, can be anything here and that it's just shorthand for repeatedly overwriting the variable. So something more akin to ...
// blocking inside an IIFE
let result = (() => {
let $;
$ = books;
$ = filter($, _ => _.title = "..."),
$ = map($, _ => _.author),
return $;
})()
The "comma" version successfully cuts out some of the noise, getting you closer to what the proposal would be:
let result = books
|> filter($, _ => _.title = "..."
|> map($, _ => _.author)
Here's another example using it to compose functions:
const double = (x) => 2 * x;
const add = (x, y) => x + y;
const boundScore = (min, max, score) => Math.max(min, Math.min(max, score));
const calculateScore = ($) => (
$= double($),
$= add($, 20),
$= boundScore(0, 100, $),
(console.log($), $)
)
const score = calculateScore(28)
The comma operator (,) evaluates each of its operands (from left to right) and returns the value of the last operand. This lets you create a compound expression in which multiple expressions are evaluated, with the compound expression's final value being the value of the rightmost of its member expressions. This is commonly used to provide multiple parameters to a for loop.
let x = 1;
x = (x++, x);
console.log(x);
// expected output: 2
x = (2, 3);
console.log(x);
// expected output: 3
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Comma_Operator
Another area where comma operator can be used is Code Obfuscation.
Let's say a developper writes some code like this:
var foo = 'bar';
Now, she decides to obfuscate the code. The tool used may changed the code like this:
var Z0b=(45,87)>(195,3)?'bar':(54,65)>(1,0)?'':'baz';// Z0b == 'bar'
Demo: http://jsfiddle.net/uvDuE/