How do I replace a character at a particular index in JavaScript?

Question

I have a string, let\'s say Hello world and I need to replace the char at index 3. How can I replace a char by specifying a index?

var str = \"h         


        

Answer 1

You can extend the string type to include the inset method:

String.prototype.append = function (index,value) {
  return this.slice(0,index) + value + this.slice(index);
};

var s = "New string";
alert(s.append(4,"complete "));

Then you can call the function: