I'm trying to simplify code below
if (a ||
node != r._start ||
(start = n + r._startOff, a = true),
a && node == r._end) { .... }
Can someone help me to separate this if condition to simplify form? (without commas)?
The code in the if condition will always run... this is the simplify version:
var doYourStuff = false;
if (a || node != r._start) {
doYourStuff = true;
} else {
start = n + r._startOff;
a = true;
if (node == r._end) {
doYourStuff = true;
}
}
if (doYourStuff) {
// ... do your stuff
}
Related
Do you have a better way to create this if / elseif sentence?
if ((navigator.userAgent.indexOf('Opera') || navigator.userAgent.indexOf('OPR')) != -1) {
this.state.isBrowserAllowed = true;
} else if (navigator.userAgent.indexOf('Chrome') != -1) {
this.state.isBrowserAllowed = true;
} else if (navigator.userAgent.indexOf('Safari') != -1) {
this.state.isBrowserAllowed = true;
} else if (navigator.userAgent.indexOf('Firefox') != -1) {
this.state.isBrowserAllowed = true;
}
I'd use a regular expression instead.
this.setState({
...this.state,
isBrowserAllowed: /Opera|OPR|Chrome|Safari|Firefox/.test(navigator.userAgent)
});
Also, as the comment notes, state should not be mutated in React - use setState instead.
I am trying to make a filter based on checkboxes.
The thing is js ignoring other conditions inside filter when one is active
filterData() {
return this.airlines.filter(x => {
if (this.filters.options.length != 0 || this.filters.airlines.length != 0) {
for (let i = 0; this.filters.options.length > i; i++) {
if (this.filters.options[i] == 0) {
return x.itineraries[0][0].stops == 0;
}
if (this.filters.options[i] == 1) {
return x.itineraries[0][0].segments[0].baggage_options[0].value > 0;
}
}
} else {
return x;
}
})
}
I know that return will stop the current loop, but is there any way to do it correctly?
Update-1: (When to filter record for every case checked OR case)
Replace for loop and all conditions in a single return by && for if and || condition for data:
var chbox = this.filters.options;
return $.inArray(0, chbox) != -1 && x.itineraries[0][0].stops == 0
|| $.inArray(1, chbox) != -1 && x.itineraries[0][0].segments[0].baggage_options[0].value > 0;
Hope this helps !!
$.inArray(value, arr) method will check for each checkboxes and will work for every checked ones .
Update-2 (When to filter record for every case checked AND case)
As per comment below, you are trying to use checkbox on demand so use below code:
var chbox = this.filters.options;
boolean condition = true;
if ($.inArray(0, chbox) != -1) {
conditon = conditon && x.itineraries[0][0].stops == 0;
}
if ($.inArray(1, chbox) != -1) {
conditon = conditon && x.itineraries[0][0].segments[0].baggage_options[0].value > 0;
}
return condition;
Your filter function is returning an object, which ideally should be a boolean value. Please refactor the code as below.
filterData() {
return this.airlines.filter(x => {
let result = false;
if (this.filters.options.length != 0 || this.filters.airlines.length != 0) {
for (let i = 0; this.filters.options.length > i; i++) {
if (this.filters.options[i] == 0) {
result = x.itineraries[0][0].stops == 0;
break;
} else if (this.filters.options[i] == 1) {
result = x.itineraries[0][0].segments[0].baggage_options[0].value > 0;
break;
}
}
}
return result;
})
}
It will make selection words starting with "p" and ending with "a". Why it didnt work?
function checkWord(word) {
if (word.charAt(0) = 'p' && word.charAt(word.length - 1) = 'a') {
return true;
} else {
return false;
}
= is used for assigning values, not checking them. Use == for checking the values and === for checking value and types. So, your code should be like:
function checkWord(word) {
if (word.charAt(0) === 'p' && word.charAt(word.length - 1) === 'a') {
return true;
} else {
return false;
}
This should do the trick.
You didn't put 2 equals to if you only put 1 equals you are assigning it and if you put 2 equals you're comparing it the. below code should help
/* Check weather the first letter is equals to p and the last letter is equals to a. */
function checkWord(word) {
let firstPAndLastA = false;
if(word != null){
if (word.charAt(0) == 'p' && word.charAt(word.length - 1) == 'a') {
firstPAndLastA = true;
} else {
firstPAndLastA = false;
}
}
return firstPAndLastA;
}
//Calling Function
console.log(checkWord("ppoa"))
Back to the basics of JavaScript. This is a question I am coming with is based on computation time speed of JavaScript If condition.
I have a logic which includes usage of if condition. The question is computing equal to value is faster OR not equal to value is faster?
if(vm.currentFeedbackObject.sendReminderLists[0].sendReminderFlag !== '' && vm.currentFeedbackObject.sendReminderLists[0].sendReminderedOn !== null)
{
vm.isReminderSectionVisible = true;
} else
{
vm.isReminderSectionVisible = false;
}
The above one computes not equal to
if(vm.currentFeedbackObject.sendReminderLists[0].sendReminderFlag === '' && vm.currentFeedbackObject.sendReminderLists[0].sendReminderedOn === null)
{
vm.isReminderSectionVisible = false;
} else
{
vm.isReminderSectionVisible = true;
}
The above one computes equal to value
which of both these is faster in execution?
Why don't you try it out? Write to your console this:
function notequal() {
if(vm.currentFeedbackObject.sendReminderLists[0].sendReminderFlag !== '' && vm.currentFeedbackObject.sendReminderLists[0].sendReminderedOn !== null)
vm.isReminderSectionVisible = true;
}
else {
vm.isReminderSectionVisible = false;
}
}
function yesequal() {
if(vm.currentFeedbackObject.sendReminderLists[0].sendReminderFlag === '' && vm.currentFeedbackObject.sendReminderLists[0].sendReminderedOn === null)
vm.isReminderSectionVisible = false;
}
else {
vm.isReminderSectionVisible = true;
}
}
var iterations = 1000000;
console.time('Notequal #1');
for(var i = 0; i < iterations; i++ ){
notequal();
};
console.timeEnd('Notequal #1')
console.time('Yesequal #2');
for(var i = 0; i < iterations; i++ ){
yesequal();
};
console.timeEnd('Yesequal #2')
I did some searching and there where others asking this question and answers to it but none that seemed to fit what I was trying to do. Basically I'm working on a validation of the phone entry that accepts (123)4567890 as an entry. I've already implemented one that accepts a simple number string such as 1234567890 and one with dashes 123-456-7890. I know I'm making a simple mistake somewehre but I can't figure out what I'm doing wrong.
Here's the phone number with dashes form that is working:
//Validates phone number with dashes.
function isTwelveAndDashes(phone) {
if (phone.length != 12) return false;
var pass = true;
for (var i = 0; i < phone.length; i++) {
var c = phone.charAt(i);
if (i == 3 || i == 7) {
if (c != '-') {
pass = false;
}
}
else {
if (!isDigit(c)) {
pass = false;
}
}
}
return pass;
}
and this is the one I can't manage to work out.
function isTwelveAndPara(phone) {
if (phone.length != 12) return false;
var pass = true;
for (var i = 0; i < phone.length; i++) {
var c = phone.charAt(i);
if (i == 0) {
if (c != '(') {
pass = false;
}
}
if (i == 4) {
if (c != ')') {
pass = false;
}
}
else {
if (!isDigit(c)) {
pass = false;
}
}
}
return pass;
}
You can do it very easily with regex:
return !!phone.match(/\(\d{3}\)\d{7}/g)
Live DEMO
Update:
The code you had didn't work because you forgot the else if:
else if (i == 4) { // Added the "else" on the left.
Checking phone number with RegEx is certainly the way to go. Here is the validation
function that ignores spaces, parentheses and dashes:
check_phone(num) {
return num.replace(/[\s\-\(\)]/g,'').match(/^\+?\d{6,10}$/) != null}
You can vary the number of digits to accept with the range in the second regular expression {6,10}. Leading + is allowed.
Something like that (a RegExp rule) can make sure it matches either rule.
var numbers = ['(1234567890','(123)4567890','123-456-7890','1234567890','12345678901'];
var rule = /^(\(\d{3}\)\d{7}|\d{3}-\d{3}-\d{4}|\d{10})$/;
for (var i = 0; i < numbers.length; i++) {
var passed = rule.test(numbers[i].replace(/\s/g,''));
console.log(numbers[i] + '\t-->\t' + (passed ? 'passed' : 'failed'));
}
EDIT:
function isDigit(num) {
return !isNaN(parseInt(num))
}
function isTwelveAndPara(phone) {
if (phone.length != 12) return false;
for (var i = 0; i < phone.length; i++) {
var c = phone.charAt(i);
if (i == 0) {
if (c != '(') return false;
} else if (i == 4) {
if (c != ')') return false;
} else if (!isDigit(c)) return false;
}
return true;
}
// or...
function isTwelveAndPara(phone) {
if (phone.length != 12 || phone.charAt(0) != '(' || phone.charAt(4) != ')') return false;
for (var i = 1; i < phone.length, i != 4; i++) {
if (!isDigit(phone.charAt(i))) return false;
}
return true;
}