First of all, I've done my research and I did find a bunch of simialr questions. However, I didn't find an answer that applies to my problem. All the examples I found were related to unescaped characters, single/double quote mishaps and the like. I on the other hand am getting this error on the following function:
$('.seq_input').blur(function(){
//var id = $(this).data('id');
//var index = parseInt($(this).val()),
//element = $("#test-list li").eq(id).remove();
//$("#test-list li").eq(index - 1).before(element); // -1 because users like 1 based indices
alert('what?');
});
As you see I commented out everything and just left an alert, and I'm still getting the error, pointing to the last line of the function. It couldn't have anything to do with other functions because I just added this one alone at the end of my current Javascript.
Can someone please tell me what's going on here? Why on Earth would a function that just alerts something (or even if it doesn't do anything) give an error?
NOTE: error is shown as soon as the page is loaded
There are invisible characters between the trailing semicolon and the parenthesis. I concatenated your code, put it in a string, and called a non-existent function in order to trigger a error (using this method).
'});'.l()
>>> TypeError: "})\u200B\u200B\u200B;".l is not a function
$('.seq_input') may used on the other functions, try using new id to do that function.
Related
I am getting some really weird syntax errors [Uncaught SyntaxError: Unexpected identifier] for seemingly normal code.
Getting an error if I write anything after the 1st line in the else block..
if (classlist.length == 0) {
lastClickCatID = -1;
}
else {
lastClickCatID = +classlist.value.split('-')[1];
// **Getting error if I write anything here, even for comments like this**
}
Getting the error if I just use two words in the comment (with a space between them). And of course getting error for any JS statements, even basic console logs.
Also, getting an error for a console.log line in the following code which has been commented out (the 4th line: console.log-"UNDO"):
// Push this data into the undo array
undo.push([lastClickDivID, lastClickCol, lastClickRow, lastClickCatID, nextClickCatID]);
//console.log("UNDO", undo[0][0], undo[0][1], undo[0][2], undo[0][3], undo[0][4]); // *Getting error if I include this line*
console.log(undo.pop());
Getting an error with or without the comment tag. But if I remove the entire line, it works fine.
I have another line:
nextClickCatID = +id2;
Again getting errors for doing a console.log of the variable. But it works fine if I remove the '+' and just use next 'nextClickCatID = id2; '.
Also getting many other weird errors like that within this function (it will get too long if I include them). Any idea why I am getting errors like these for seemingly normal code?
I have solved it. It strangely worked when I removed the space between the () and the curly brackets in the jquery document ready function. Changed from...
$(function() {
to:
$(function(){ // with no space between the parentheses and the curly brackets
I want to add that - it was working fine before with the same structure (with space in between brackets) all this while. But suddenly decided to give an error today in a particular function. If somebody can clarify why this happened, it will still be very relevant.
I have a very specific problem concerning a regular expression matching in Javascript. I'm trying to match a piece of source code, more specifically a portion here:
<TD WIDTH=100% ALIGN=right>World Boards | Olympa - Trade | <b>Bump when Yasir...</b></TD>
The part I'm trying to match is boardid=106121">Olympa - Trade</a>, the part I actually need is "Olympa". So I use the following line of JS code to get a match and have "Olympa" returned:
var world = document.documentElement.innerHTML.match('/boardid=[0-9]+">([A-Z][a-z]+)( - Trade){0,1}<\/a>/i')[1];
the ( - Trade) part is optional in my problem, hence the {0,1} in the regex.
There's also no easier way to narrow down the code by e.g. getElementsByTagName, so searching the complete source code is my only option.
Now here's the funny thing. I have used two online regex matchers (of which one was for JS-regex specifically) to test my regex against the complete source code. Both times, it had a match and returned "Olympa" exactly as it should have. However, when I have Chrome include the script on the actual page, it gives the following error:
Error in event handler for 'undefined': Cannot read property '1' of null TypeError: Cannot read property '1' of null
Obviously, the first part of my line returns "null" because it does not find a match, and taking [1] of "null" doesn't work.
I figured I might not be doing the match on the source code, but when I let the script output document.documentElement.innerHTML to the console, it outputs the complete source code.
I see no reason why this regex fails, so I must be overlooking something very silly. Does anyone else see the problem?
All help appreciated,
Kenneth
You're putting your regular expression inside a string. It should not be inside a string.
var world = document.documentElement.innerHTML.match(/boardid=[0-9]+">([A-Z][a-z]+)( - Trade){0,1}<\/a>/i)[1];
Another thing — it appears you have a document object, in which case all this HTML is already parsed for you, and you can take advantage of that instead of reinventing a fragile wheel.
var element = document.querySelector('a[href*="boardid="]');
var world = element.textContent;
(This assumes that you don't need <=IE8 support. If you do, there remains a better way, though.)
(P.S. ? is shorthand for {0,1}.)
I'm a newbie to javascript and jquery, and this bug has been hounding me for almost a day. Here's the code:
$('#txtTabContentsHeight', '#ddlTabContentsHeightRuler').blur(function ()
{
//need to check ruler val first!
var sruler = $('#ddlTabContentsHeightRuler').children("option").filter(":selected").text().toLowerCase();
var sval = $('#txtTabContentsHeight').val(); + '' + sruler;
ChangeTabContentsCss(this, 'height');
});
I get a jquery error in my browser console on the $('#ddl...').^^children(... line. Even if I do a $('#ddlTabContentsHeightRuler').val(), I get the same error on the '.' of invalid or unexpected token.
I've checked every single similar discussion here and on the web for this kind of error, and it's always about a string issue, or a syntax issue. But for the life of me, I can't see a syntax problem here. The ddl element is a select element, obviously.
Can someone smack me upside the head with an answer?
Try changing .text() for .val() or .html(). The .text() method cannot be used on form inputs
did u need the semi-colon on $('#txtTabContentsHeight').val(); + '' + sruler;or
$('#txtTabContentsHeight').val() + '' + sruler;
Well, as usual when I have these kinds of errors, if I just RETYPED the whole line, the bug disappeared! I actually did an undo, and tried to delete every single character on the original line, to see if I had some 'hidden characters' or something...and NOPE. Still got the error, though the line looked EXACTLY the same as the one that works.
Is this usual with jquery/javascript? That's sort of unacceptable as a programmer...
As earlier suggested, you could use with cross checking your html code especially the id names of the elements being selected
I'm a beginner in jquery and ajax. While i was going through some example online, i came across the following piece of code and wondered what exactly it does.
lines = newLine.split('#');
jQuery.each(lines, function(lineNo, line) {
eval("linedata = " + line);
data.push(linedata);
});
I'm not a programmer, but just trying to understand its functionality. Can anyone help me?
The each function iterates over an array which is supplied as the first parameter. During each iteration the index and element are passed into a function that is performed. The function is passed as the second parameter to the each function.
Read more on the jQuery Documentation
In the example you have provided a string newLine is split into an array using # as the delimiter.
The each function then iterates over the newly created array, assigning the value of each element to a variable linedata and pushes linedata onto another array.
This could be more easily achieved with the following, since the call to eval is unnecessary:
jQuery.each(lines, function(lineNo, line) {
data.push(line);
});
I pretended, for a moment, that I was a new programmer. This is how you should go about looking into things from here on out:
1.) Ok, I don't know what this first line is doing. It's splitting something (based on the split word). Hmmm let's Google for "split javascript". This is the first thing that comes up. From here, you may be wondering what a String is, so you would search for that as well).
2.) Ok so now I know that splitting a String gives me an array (again you probably looked this up by this step) of the newLine substrings that were separated by the # character. Cool. So let's look into what jQuery.each does. I google "jQuery.each" and this is the first thing that comes up.
Awesome! Now you understand what a String is, an Array, the split function from String as well as what jQuery.each is. :D
EDIT: As you move forward, you'll realize that W3C is generally an inferior source of information. I simply linked to it since it was literally the first thing that came up when I Googled "split javascript". Overall it does the job for giving you a good overview of certain things when you're learning them for the first time.
I'm making a library, and I often inspect the result of Closure Compiler's output to see how it's doing things (I do have unit tests, but I still like to see the compiled code for hints of how it could compress better).
So, I found this very weird piece of code, which I never seen before.
variable : {
some();
code()
}
Note: this is not an object literal! Also, there is no ? anywhere that would make it a ?: conditional.
That code is in a regular function block (an IIFE).
variable, in this case, is an undefined variable. There's no code making it true, false, or whatever, and just to make sure, I put a console.log in there and indeed, I get a ReferenceError.
Please do note that I test my code in IE8 too, so this isn't just in modern browsers. It seems to be standard, plain old javascript.
So let's experiment with it. Firing up Chrome's console, I get this:
undeclaredVariable:{console.log('does this get logged?')} // yes it does.
trueValue:{console.log('what about this?')} // same thing.
falseValue:{console.log('and this?')} // same thing.
but then...
(true):{console.log('does this work too?')} // SyntaxError: Unexpected token :
...and...
so?{console.log('is this a conditional?')}:{alert(123)} // Unexpected token .
So what does it do?
thisThing:{console.log('is used to declare a variable?')}
thisThing // ReferenceError: thisThing is not defined
Please, I'd love it if someone could explain to me what this code is meant to do, or at least what it does.
It is a label
Provides a statement with an identifier that you can refer to using a
break or continue statement.
For example, you can use a label to identify a loop, and then use the
break or continue statements to indicate whether a program should
interrupt the loop or continue its execution.
Another common place you see it is when people stick the wonderful and useless javascript: on event handlers.
This is a label (the bit ending with a colon) followed by a block (the code surrounded by the curly brackets).
Blocks usually follow control statements, like if(...) { /*block*/ }, but they can also simply stand on their own, as in your example.
Labels allow jumping up several loops at a time with a continue or break; see the linked MDN page for several examples, such as:
var itemsPassed = 0;
var i, j;
top:
for (i = 0; i < items.length; i++){
for (j = 0; j < tests.length; j++)
if (!tests[j].pass(items[i]))
continue top;
itemsPassed++;
}
Here, top: is a label that code inside the inner loop can jump to, in order to escape to the outer loop.
For the sake of anyone who doesn't know what JSON is, and sees a colon in what might actually be an object, and is trying to figure out what it is, and finds this discussion, a colon is also used in JSON. There is a practice of embedding functions in a JSON object. Which might be confusing (As it was to me) for anyone who happens to see this for the first time. (Everyone isn't born with the knowledge of JSON and JavaScript programmed into their brains.) So if you find yourself at this discussion, and you think that every time you see a colon in JavaScript, that it's a label, it might not be. It might be that it's a colon after a label, OR it might be part of JSON. In fact, a colon in JSON being shown as a string, is a lot more common than a label. JSON in the form of an object, will be displayed as [object Object], with all the content hidden. So, unless the JSON is in the form of a string, and you display an object to the console (console.log(object)) all you will see is [object Object]. It is common practice to write JavaScript code, wrapped in an object. In that case you will see the JSON in the form of code. That's when you'll ask yourself, "What is this? and what is that colon for?" Then you'll find yourself at this discussion, and be told that it's a label, when it's really part of JSON. The topic of this discussion is worded: "Please explain this usage of a colon in javascript", and then the "correct answer" is marked as having to do with a label. The correct answer is that a colon can be used in more than one way. So, if you don't know what JSON is, or think you know (like I did, but didn't really understand) read about it here:
JSON.org
That is just a label.
you can use continue [label name] (or break) in a loop to go to a label.
More explanations of what they are can be seen throughout the interwebs.
it is used for labeling an statement in jsvascript.check more detail here.
the labeled statement can be used with break and continue later.