javascript replace all instances of value in string code example

Example 1: javascript count occurrences in string

function countOccurences(string, word) {
   return string.split(word).length - 1;
}
var text="We went down to the stall, then down to the river."; 
var count=countOccurences(text,"down"); // 2

Example 2: javascript convert in a string the items of an array

const arr = [1, 2, 'a', '1a'];
const str = arr.toString();
console.log(str); //> "1,2,a,1a"