replace all character in string javascript

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"); 

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

str.replace(/hello/g, 'hi');
// the g is to show it's a global change, not one-time change.

str.replace(new RegExp('hello', 'g'), 'hi');

str = str.replace(new RegExp('abc', 'g'), 'xyz');

let a = "How to search and replace a char in a string";
while (a.search(" ", ""))
{
   a = a.replace(" ", "");
}
console.log(a);