javascript change letter in string code example

Example 1: replacing characters in string javascript

var myStr = 'this,is,a,test';
var newStr = myStr.replace(/,/g, '-');

console.log( newStr );  // "this-is-a-test"

Example 2: javascript string change character at index

String.prototype.replaceAt=function(index, char) {
    var a = this.split("");
    a[index] = char;
    return a.join("");
}

Example 3: string one char change in typescript

let hello:string = "Hello World";
console.log(hello.replaceAt(2, "!!")); // Should display He!!o World