如何获取特定键值的数组？

Question

var obj = [
  {
    "amount": " 12185",
    "job": "GAPA",
    "month": "JANUARY",
    "year": "2010"
  },
  {
    "amount": "147421",
    "job": "GAPA",
    "month": "MAY",
    "year": "2010"
  },
  {
    "amount": "2347",
    "job": "GAPA",
    "month": "AUGUST",
    "year": "2010"
  }
]

How can i get all amounts, that is '12185' , '147421' , '2347' . I've tried to do this

Object.keys(obj).map(key => obj[key])

Answer 1

Your obj variable is actually an array. (denoted by the braces [] )

You can use the map function on an array to return what you're asking for.

var amounts = obj.map(x => x.amount); // Array(3) [ " 12185", "147421", "2347" ]

You may also want to append .trim() to the end of x.amount to remove any spaces specifically.

var amounts = obj.map(x => x.amount.trim()); // Array(3) [ "12185", "147421", "2347" ]

var obj = [
  {
    "amount": " 12185",
    "job": "GAPA",
    "month": "JANUARY",
    "year": "2010"
  },
  {
    "amount": "147421",
    "job": "GAPA",
    "month": "MAY",
    "year": "2010"
  },
  {
    "amount": "2347",
    "job": "GAPA",
    "month": "AUGUST",
    "year": "2010"
  }
];


var amounts = obj.map(x => x.amount);

console.log(keys); // Array(3) [ " 12185", "147421", "2347" ]

Answer 2

你的obj是一个数组，你需要：

const vals = obj.map(entry => entry.amount); // ["12185", "147421", "2347"]

Answer 3

I believe you're looking for this

 var obj = [ { "amount": " 12185", "job": "GAPA", "month": "JANUARY", "year": "2010" }, { "amount": "147421", "job": "GAPA", "month": "MAY", "year": "2010" }, { "amount": "2347", "job": "GAPA", "month": "AUGUST", "year": "2010" } ]; let amounts = obj.map(v => v.amount); console.log(amounts);