CODEWITHSUNDEEP
javascriptregex
fish man
fish man

Reputation: 2700

javascript replace with regex

How to use javascript replace with regex in this situation?

<div id="content" style="left: 200px">
=><div id="content" style="left: -200px">

var num = $('#content').attr('style');
alert(num.replace.replace('/[0-9]+/g','-\\$1'));


<div id="content" style="left: -200px">
=><div id="content" style="left: 200px">

var num = $('#content').attr('style');
alert(num.replace.replace('/-[0-9]+/g','\\$1'));

my code seems not work, need a help. thanx.

Upvotes: 0

Views: 132

Answers (4)

user1636522
user1636522

Reputation:

Just do this :

$('#content').css('left', function (i, value) {
    return -parseInt(value);
});

Here is a demo (click the red box) : http://jsfiddle.net/wared/s6M43/.

Upvotes: 1

shyam
shyam

Reputation: 9368

replace also takes a function so, you can do something like

var str = '<div id="content" style="left: 200px"> => <div id="content" style="left: -200px">';
str.replace(/(-?)([0-9]+)/g, function(match, sign, px) { return '-' == sign ? px : '-' + px })
//'<div id="content" style="left: -200px"> => <div id="content" style="left: 200px">'

Upvotes: 0

OGHaza
OGHaza

Reputation: 4795

$1 refers to the first capture group - of which you have none. As John says you can use $& to refer to the entire match.

To use $1 you would need to put () around your match to create the capture group /([0-9]+)/g

Upvotes: 1

John Strickler
John Strickler

Reputation: 25421

Use $& to signify the matched value in the 2nd argument. This is a JavaScript feature of .replace and not a feature of regular expressions.

var x = "left: 200px".replace(/\d+/,'-$&')
// x == "left: -200px"

Upvotes: 2

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