dynamic global value replacement in javascript

Question

<html>
<body>

<script type="text/javascript">

var str="Welcome to Microsoft! ";
var val="Microsoft!";

document.write(str.replace('/'+val'+/gi', "W3Schools"));

</script>

</body>
</html>

this is not working, how to use val dynamically ?

http://stackoverflow.com/questions/494035/how-do-you-pass-a-variable-to-a-regular-expression-javascript — , Mar 28 '12 at 11:32

score 2 · Answer 1 · answered Mar 28 '12 at 11:24

2

You need to make the argument for replace() a regular expression. If you put it in quotes, it is simply a string. Use the RegExp constructor instead:

document.write(str.replace(new RegExp(val, 'gi'), "W3Schools"));

answered Mar 28 '12 at 11:24

Niko

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score 1 · Accepted Answer · answered Mar 28 '12 at 11:25

You cannot construct a regex literal trough string concatenation

try:

var str="Welcome to Microsoft! ";
var val="Microsoft!";

document.write(str.replace(new RegExp(val, 'gi'), "http://www.w3fools.com"));

Ref: https://developer.mozilla.org/en/JavaScript/Guide/Regular_Expressions

dynamic global value replacement in javascript

2 Answers2