js统计某个字符串在另一个字符串中出现的次数

var childInNums = parent.split(child).length - 1;

function strCount(str, target) {
  let count = 0
  if (!target) return count
  while(str.match(target)) {
    str = str.replace(target, '')
    count++
  }
  return count
}

console.log(strCount('abcdef abcdef a', 'abc'))

function substrCount(str, target) {
  let count = 0;
  while (str.includes(target)) {
    const index = str.indexOf(target);
    count++;
    str = str.substring(index + target.length);
  }
  return count;
}