Regex to match carriage return in Javascript - Stack Overflow

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I am trying to write some Javascript to hide some elements that contain only carriage returns. I appreciate that the correct way to solve this problem would be to stop these elements being created, but unfortunately that is not possible in this instance. I am trying to user a regular expression to search for the unwanted elements but am not having much luck. The function I have written is as follows:

function HideEmptyP()
{

    var patt = (\\r)
    for(var i = 0;i<desc[i].length;i++);
    {
    var desc[i] = document.getElementsByClassName('sitspagedesc');
    var result[i] = patt.test(desc[i]);
        if (result[i] == true)
            {
            desc[i].style.display='none';
            }
        else
            {
            alert("No Match!");
            }
    }

The error I'm getting in the Web Console is 'Syntax Error: Illegal Character'.

Grateful for any ideas on how to solve this.

Thanks in advance.

I am trying to write some Javascript to hide some elements that contain only carriage returns. I appreciate that the correct way to solve this problem would be to stop these elements being created, but unfortunately that is not possible in this instance. I am trying to user a regular expression to search for the unwanted elements but am not having much luck. The function I have written is as follows:

function HideEmptyP()
{

    var patt = (\\r)
    for(var i = 0;i<desc[i].length;i++);
    {
    var desc[i] = document.getElementsByClassName('sitspagedesc');
    var result[i] = patt.test(desc[i]);
        if (result[i] == true)
            {
            desc[i].style.display='none';
            }
        else
            {
            alert("No Match!");
            }
    }

The error I'm getting in the Web Console is 'Syntax Error: Illegal Character'.

Grateful for any ideas on how to solve this.

Thanks in advance.

• javascript
• regex

Share Improve this question Follow edited Nov 23, 2012 at 10:33 Andy Kaufman asked Nov 23, 2012 at 10:28 Andy KaufmanAndy Kaufman 78133 gold badges99 silver badges2323 bronze badges 1

• 1 var patt = (\\r) <== incorrect syntax – elclanrs Commented Nov 23, 2012 at 10:31

Add a ment  | 

4 Answers 4

Sorted by: Reset to default 7

I am trying to write some Javascript to hide some elements that contain only carriage returns.

There's no need for a regular expression for that, just pare the element's innerHTML property to "\\r", e.g.:

if (demo[i].innerHTML === "\\r") {
    // Remove it
}

But beware that some browsers may transform a single carriage return. You might want to check for "\\r", "\\n", and just a space. To do that, you might want to use a regular expression.

Your regular expression literal ((\\r)) is just pletely invalid, it's worth reading up on them to learn the correct syntax. To write a regular expression literal in JavaScript, you use / as the delimiter. So: /\\r/. To test that a string contains only \r, \n, or space, you can use /^[\r\n ]+$/ (which requires there be at least one character that matches, and uses ^ to indicate start-of-string, and $ to indicate end-of-string):

if (demo[i].innerHTML.match(/^[\r\n ]+$/) {
    // Remove it
}

The reason you are getting Syntax error is because the declaration var patt = (\r) is incorrect it should be somethign like var patt = '\r';

Also the whole for loop is wrong.

You should define demo before you start the for loop not inside it, and result need not be an array but just a normal variable

Your litteral seems odd.

Try var patt = /\r/;

var patt=/\n/gi   

should work.

extra i flag to denote case insensitive. g for global search.

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