var str = "Hello Lewes"; var ch = 'e'; var count = str.split("e").length - 1; console.log(count); /* Output: 3 */
const recorrences = ['a', 'b', 'c', 'a', 'b','a'] .map(i => !!~i.indexOf('a')) .filter(i => i) .length; console.log(`recorrences ${recorrences}`) //recorrences 3
let counter = str => { return str.split('').reduce((total, letter) => { total[letter] ? total[letter]++ : total[letter] = 1; return total; }, {}); }; counter("aabsssd"); // => { a: 2, b: 1, s: 3, d: 1 }