Simple Javascript replace with a loop

Question

I'm try to replace all occurances wihtin a string with the array index value as below.

var str = '<a href="{0}" title="{1}">{1}</a>';
var params= [];
params.push('Url', 'TitleDisplay');
for (i in params) {
 var x = /'{' + i + '}'/g;
 str = str.replace(x, params[i]);
}

No matter what I do, I cannot seem to get it to work. Dropping the '/g' works with one match, but not all. I know this is basic but for the lide of me I cannot get it to work.

• Andreas: Don't use for... in... for arrays

Answer 1

Fiddle here

Code:

var rx = /{([0-9]+)}/g;
str=str.replace(rx,function(0,ドル1ドル){return params[1ドル];});

The replace method loops through the string (because of /g in the regex) and finds all instances of {n} where n is a number. 1ドル captures the number and the function replaces {n} with params[n].

Answer 2

try using this:

var x = new RegExp("\\{" + i + "\\}", "g");

instead of this:

var x = /'{' + i + '}'/g;

Answer 3

You can build a regexp object if you need it to be dynamic

var str = '<a href="{0}" title="{1}">{1}</a>';
var params= [];
params.push('Url', 'TitleDisplay');
for (var i = 0; i < params.length; i++) {
 var x = new RegExp('(\\{'+i+'\\})', 'g');
 str = str.replace(x, params[i]);
}
alert(str);
​

http://jsfiddle.net/LByBT/

Answer 4

How about this if you would like to skip a regex solution ..

function replaceAllOccurrences(inputString, oldStr, newStr) 
{
 while (inputString.indexOf(oldStr) >= 0)
 {
 inputString = inputString.replace(oldStr, newStr);
 }
 return inputString;
}

• Gene Bo: Can you share your code and the input strings you use - for me I use this successfully across a variety of projects
• Vasil Gerginski: @emotality that is because probably you are replacing a string with the same string with something in front of or at the end of it