String duplicate check (each character of the query string appears several times in total)

String duplicate check (each character of the query string appears several times in total)

Directly on the code:

//又名哈希查重
  let str = "hello world";

  function fn(str){
    let obj = {};
    str.replace(/\S/g,function(a){
      obj[a] ? obj[a]++ : obj[a] = 1;
    })
    return obj
  }
  console.log(fn(str))