JSON数组，封装根据属性查找数组对象的方法

  Array.prototype.chooseSomeone = function(param, exeparam) {
      let item
      for (let i = 0; i < this.length; i++) {
        if (this[i][param] == exeparam) {
          item = this[i]
        }
      }
      return item
    }

//调用
let arr =[{id:3,name:"小胖娃娃"},{id:4,name:"小瘦娃娃"}]
arr.chooseSomeone("id",3) // {id:3,name:"小胖娃娃"}