replaceAll() in Javascript without jQuery

replaceAll() is very basic and useful string function, but surprise JavaScript has replace() but no replaceAll().

When we are going to use replace() in any string, most of the times it is not easy to predict how many occurrence we will have to replace. There can be many approach to do it, let's have a look to all then proceed to best one.

1. Use Fail-Safe

Using more replace() in chain than expected occurrences, this will not harm in anyway but it is not a good practice if because no. of occurrence is not predictable.

var StrToRepalce ="Scala is a Functional Programming Language. Scala is easy to learn.";

StrToRepalce = StrToRepalce.replace('Scala', 'F#')
.replace('Scala', 'F#')
.replace('Scala', 'F#')
.replace('Scala', 'F#');

console.log(StrToRepalce);

2. split() join() combination

This approach will work for any number of occurrences, but more performance costly.

var StrToRepalce ="Scala is a Functional Programming Language. Scala is easy to learn.";

StrToRepalce = StrToRepalce.split("Scala").join("F#");

console.log(StrToRepalce);

3. Using Regular Expression

Very short and simple regex will work for any no. of occurrences, but error prone for special characters.

var StrToRepalce ="Scala is a Functional Programming Language. Scala is easy to learn.";

StrToRepalce = StrToRepalce.replace(/Scala/g, 'F#');

console.log(StrToRepalce);

4. RegEx with Special Character handling

Same as previous approach but will handle special characters too.

var StrToRepalce ="Scala is a Functional Programming Language. Scala is easy to learn.";

StrToRepalce = StrToRepalce.replace(new RegExp("Scala".replace(/[-\/\\^$*+?.()|[\]{}]/g, '\\$&'), 'g'), "F#");

console.log(StrToRepalce);

5. Adding replaceAll() to string prototype to use globally

Above approach is all good, but it is better to place this function to string prototype so can be can from any where across application.

String.prototype.replaceAll = function (find, replace) {
    var str = this;
    return str.replace(new RegExp(find.replace(/[-\/\\^$*+?.()|[\]{}]/g, '\\$&'), 'g'), replace);
};

var StrToRepalce ="Scala is a Functional Programming Language. Scala is easy to learn.";

StrToRepalce = StrToRepalce.replaceAll("Scala", "F#");

console.log(StrToRepalce);