JSON / Javascript：返回哪个数组对象包含某个属性

Question

Given a JSON object such as this:

{
  "something": {
    "terms": [
      {
        "span": [
          15,
          16
        ],
        "value": ":",
        "label": "separator"
      },
      {
        "span": [
          16,
          20
        ],
        "value": "12.5",
        "label": "number"
      }
    ],
    "span": [
      15,
      20
    ],
    "weight": 0.005,
    "value": ":12.5"
  }

I would like write some javascript that would determine the index of the "term" that has a "label": "number". Ultimately I want to determine the "value" of the "term" that has a "label": "number", I know I can get that with something like this, where the index is known:

parsed = JSON.parse(result.trim());
var numberValue = parsed.terms[1].value;

My first thought is perhaps to just write a foreach loop and then return the numberValue when I arrive at an array object that has "label": "number".

Is there a more elegant and/or concise way to do this?

Answer 1

Use Array.prototype.filter :

var numberValue, list = parsed.something.terms.filter(function(a){
  return a.label==='number';
});
numberValue = list.length ? list[0].value : -1;