JavaScript RegExp in replace() not working [duplicate]

Answer 1

Because in string literals, \ has a special meaning. If you want to actually put a \ in the regular expression, you need to escape it in the string literal:

new RegExp("\\:\\$" + i, "g")

But : has no special meaning in regular expressions, no need to escape it:

new RegExp(":\\$" + i, "g")

var str = "Some text :$0";
var i = 0;

console.log(str.replace(new RegExp(":\\$" + i, "g"), 'here'));