javascript - 双for循环没有得到返回数据

Question

为什么我的代码不是count？

var a = {
  count: [{label:'a', value: 'a'}],
  next: [{label:'b', value: 'b'}],
  previous: [{label:'c', value: 'c'}],
}

function get_item() {

  var x = "a"

  for (let item in a){
    a[item].forEach(obj => {
      console.log(obj.value, x )   
      if(obj.value === x) {
        return item
      }
    })
  }
}


console.log(get_item())

控制台日志如下:

a a
b a
c a
undefined

你看到了a a，但为什么它没有看到count而不是undefined？

Answer 1

以下解决方案可能适合您:

 var a = {
        count: [{label:'a', value: 'a'}],
        next: [{label:'b', value: 'b'}],
        previous: [{label:'c', value: 'c'}]
       }
    function get_item() {
           var x = "a"
           for (let item in a){
            let resultItem = a[item].find((obj)=>{ return obj.value === x });
            if(resultItem) return item //you can also return 'resultItem';
            }
          }
          console.log(get_item())