문자 찾기

• 일반 문자열

const solution = (string, target) =>
  string.split('').filter(char => char == target).length;

const result = solution('COMPUTERPROGRAMMING', 'R');
console.log(result);

• 정규표현식

const solution = (string, target) => {
  const regex = new RegExp(`${target}`, 'g');
  return string.match(regex).length;
};

const result = solution('COMPUTERPROGRAMMING', 'R');
console.log(result);