I would like to create a String.replaceAll()
method in JavaScript and think using a regex would be the most terse way to do it. However, I can't figure out how to pass a variable into a regex. I can do this already which will replace all the instances of "B"
with "A"
.
"ABABAB".replace(/B/g, "A");
But I want to do something like this:
String.prototype.replaceAll = function(replaceThis, withThis) {
this.replace(/replaceThis/g, withThis);
};
But obviously, this will only replace the text "replaceThis"
...so how do I pass this variable into my regex string?
Instead of using the /\sREGEX\s/g
syntax, you can construct a new RegExp object:
// variable == 'REGEX'
let re = new RegExp(String.raw`\s${variable}\s`, "g");
You can dynamically create regex objects this way. Then you will do:
"mystring1".replace(re, "newstring");
// variable == 'REGEX'
var re = new RegExp("\\s" + variable + "\\s", "g");
"mystring1".replace(re, "newstring");