Online Node.js Compiler

const num = 100; const countNine = (num = 0) => { const countChar = (str = '', char = '') => { return str .split('') .reduce((acc, val) => { if(val === char){ acc++; } return acc; }, 0); }; let count = 0; for(let i = 0; i <= num; i++){ count += countChar(String(i), '9'); } return count; }; console.log(countNine(num));