replace only sub string which has class highlight javascript

Question

I have the following code:

document.getElementById("rep").innerHTML = document.getElementById("rep").innerHTML.replace(rxp, "abc");

<div id="rep"> asd 123 asd <span class="light">123</span> asd 123 asd <span class="light">123</span> </div>

Here, rxp is a regular expression which matches the numbers. Problem is that I want to replace only those 123 that are not enclosed in span and not to replace 123 which enclosed in <span class="light">.

Wiktor Stribiżew · Accepted Answer · 2015-05-14 09:19:27Z

2

You can use the reverse string trick to leverage a negative look-ahead instead of a negative look-behind (that is not supported by the JavaScript regex engine):

function revStr(str) {
    return str.split('').reverse().join('');
}

var rxp = new RegExp("[0-9]+(?:\\.[0-9]+)?(?![^>]*>\"thgil\"=ssalc\\s+naps<)", "gm");
var str = '<div id="rep"> asd 123 asd <span class="light">123</span> asd 123 asd <span class="light">123</span> </div>';
var result = revStr(revStr(str).replace(rxp, revStr('abc')));
document.getElementById("res").value = result;

<input id="res"/>

You should also use a reversed replacement string.

EDIT: In case you need to check if the number is not enclosed in any <span> tag with any attributes, you can use a simpler regex:

var rxp = new RegExp("[0-9]+(?:\\.[0-9]+)?(?![^>]*>[^>]*\\bnaps<)", "gm");

edited May 14, 2015 at 9:19

answered May 14, 2015 at 7:54

Wiktor Stribiżew

631k41 gold badges502 silver badges632 bronze badges

Sign up to request clarification or add additional context in comments.

5 Comments

EMM Over a year ago

And what if the regular expression for numbers is this: var rxp = new RegExp("(([0-9]+\.?[0-9]+)|([0-9]+))", "gm");

Wiktor Stribiżew Over a year ago

I do not see any problems since you are only matching digits and an optional dot between the numbers: var rxp = new RegExp("[0-9]+(?:\\.[0-9]+)?(?![^>]*>\"thgil\"=ssalc\\s+naps<)", "gm");. EDIT: I removed \b word boundary, perhaps, you also need to remove digits even in case of xxx123.

Lorenz Meyer Over a year ago

This is a really creative solution

EMM Over a year ago

@stribizhev I have a little problem that if class of span is not light, I mean if it will something that I don't know then what will be the regular expression?

Wiktor Stribiżew Over a year ago

@EMM: @EMM: It will be even easier: var rxp = new RegExp("[0-9]+(?:\\.[0-9]+)?(?![^>]*>[^<]*\\bnaps<)", "gm");. Sample code here

Collectives™ on Stack Overflow

replace only sub string which has class highlight javascript

1 Answer 1

5 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

5 Comments

Your Answer

Sign up or log in

Post as a guest

Related