how to replace specific characters javascript code example

Example 1: js replace characters in a string

var str = "Original string!";
var str = str.replace("Original", "New");

Example 2: javascript replace all occurrences of string

function replaceAll(str, find, replace) {
    var escapedFind=find.replace(/([.*+?^=!:${}()|\[\]\/\\])/g, "\\$1");
    return str.replace(new RegExp(escapedFind, 'g'), replace);
}
//usage example
var sentence="How many shots did Bill take last night? That Bill is so crazy!";
var blameSusan=replaceAll(sentence,"Bill","Susan");