给定一个JSON对象，如何根据Key查找项目？

Question

给定一个JSON对象，如：

var data = {items: [
{value: "21", name: "Mick Jagger"},
{value: "43", name: "Johnny Storm"},
{value: "46", name: "Richard Hatch"},
{value: "54", name: "Kelly Slater"},
{value: "55", name: "Rudy Hamilton"},
{value: "79", name: "Michael Jordan"}
]};

我该怎么做这样的事情：

datagood = data.where(value == 55)

使用JS / jQuery是可能的吗？ 谢谢

Answer 1

jQuery的grep函数允许您过滤数组：

var datagood = $.grep(data.items, function (item) {
    return item.value == 55;
});

如果您想要更强大的实用程序，请查看JS LINQ库上的这个SO问题 。

或者， underscore.js对于数组/对象操作也很有用。

Answer 2

JLINQ？ http://www.hugoware.net/Projects/jLinq

Answer 3

您可以使用罗短跑或下划线库_.where（）和_.find（）函数：

var res1 = _.where(data.items,{value:"55"});
var res2 = _.find(data.items,{value:"55"});

这两个函数之间的区别是_.where（）返回所有匹配的记录，而_.find（） - 只返回第一个记录。

 var data = {items: [ {value: "21", name: "Mick Jagger"}, {value: "43", name: "Johnny Storm"}, {value: "46", name: "Richard Hatch"}, {value: "54", name: "Kelly Slater"}, {value: "55", name: "Rudy Hamilton"}, {value: "79", name: "Michael Jordan"}, {value: "55", name: "Another Rudy Hamilton"} ]}; var res1 = _.where(data.items,{value:"55"}); var res2 = _.find(data.items,{value:"55"}); document.write('-.where(): ',JSON.stringify(res1),'<br>'); document.write('-.find(): ',JSON.stringify(res2),'<br>'); 

 <script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/2.4.1/lodash.js"></script> 

Answer 4

var data = {items: [
{value: "21", name: "Mick Jagger"},
{value: "43", name: "Johnny Storm"},
{value: "46", name: "Richard Hatch"},
{value: "54", name: "Kelly Slater"},
{value: "55", name: "Rudy Hamilton"},
{value: "79", name: "Michael Jordan"}
]};

// using underscore.js http://documentcloud.github.com/underscore/
var t = _(data.items).find(function(x) {
  return x.value == 55;
});

JSON.stringify(t) ; //# => {"value":"55","name":"Rudy Hamilton"}

// using pure javascript
var find = function(items, f) {
  for (var i=0; i < items.length; i++) {
    var item = items[i];
    if (f(item)) return item;
  };
}

t = find(data.items, function(x) {return x.value == "55";});

JSON.stringify(t) ; //# => {"value":"55","name":"Rudy Hamilton"}