Question

我有JSON结构如下

var listOfPlays = classRoom: [
    {
        title: "Dollhouse",
        femaleLead: true,
        student: [
            { name: "Echo", role: "doll" },
            { name: "Topher", role: "mad scientist" }
        ]
    },
    {
        title: "Dr. Horrible's Sing-Along Blog",
        student: [
            { name: "Billy", role: "mad scientist" },
            { name: "Penny", role: "love interest" }
        ]
    }
]

我对Underscore.js中的_.where基本了解它会查看列表中的每个值，返回包含属性中列出的所有键值对的所有值的数组。

例如_.where(listOfPlays, {title: "Dollhouse"});这将返回一个标题为“Dollhouse”的对象，但是如何根据 student 数组的值获得对象？来自listOfPlays？

我正在寻找类似的东西：

_.where(listOfPlays  , {student: [name : "Echo"]});**

Answer 1

您正在寻找的Copy to another location方式在新版本中不再有效。

您可以使用：

_.filter查看列表中的每个值，返回通过真值测试（谓词）的所有值的数组

_.some如果列表中的任何值通过谓词真值测试，则返回true。

_.where(listOfPlays , {student: [name : "Echo"]});

var listOfPlays = [{
    title: "Dollhouse",
    femaleLead: true,
    student: [{
        name: "Echo",
        role: "doll"
      },
      {
        name: "Topher",
        role: "mad scientist"
      }
    ]
  },
  {
    title: "Dr. Horrible's Sing-Along Blog",
    student: [{
        name: "Billy",
        role: "mad scientist"
      },
      {
        name: "Penny",
        role: "love interest"
      }
    ]
  }
]

var output = _.filter(listOfPlays, function(item) {
  return _.some(item.student, {
    name: "Echo"
  });
});
console.log(output);

如何使用_.where（list，properties）将内部数组作为属性？

1 个答案: