es6 replace all string javascript code example

Example 1: javascript replace string

var str = "JavaScript replace method test";
var res = str.replace("test", "success");  
//res = Javscript replace method success

Example 2: replace all character in string javascript

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