D3.js中的数组查找

 d3.map(array, function(d) { return d.key; });

然后,您可以通过以下方式访问地图中的项目:

 map.get("value");

或检查是否存在此类值:

 map.has("value");

见 docs 更多信息。

下面是您的数据集的一个示例:

var out = [
    {name:"John", car:"bmw", colour:"blue"},
    {name:"Joe", car:"ford", colour:"red"},
    {name:"Anna", car:"honda", colour:"green"},
    {name:"Mary", car:"bmw", colour:"red"},
];


var map = d3.map(out, function(d) { return d.name; });

// Get items by key:
console.log(map.get("John").car);
console.log(map.get("Anna").colour);

// Check to see if an item exists:
console.log(map.has("Joe"));

// Create a new value and access:
map.set("Ralph", {name: "Ralph",car:"bmw",colour:"red"})
console.log(map.get("Ralph"));

<script src="https://d3js.org/d3.v4.min.js"></script>

当然,您不需要使用d3来实现这一点,常规的ES6地图(或无数其他选项)也可以同样轻松地工作:

var out = [
    {name:"John", car:"bmw", colour:"blue"},
    {name:"Joe", car:"ford", colour:"red"},
    {name:"Anna", car:"honda", colour:"green"},
    {name:"Mary", car:"bmw", colour:"red"},
];

var map = new Map(out.map(function(d) {
  return [d.name,d];
}));

console.log(map.get("John"));

你可以用 Array.prototype.find() 方法,它将返回整个对象,包括 car , colour ,以及给定的 name

var out = [
    {name:'John', car:'bmw', colour:'blue'},
    {name:'Joe', car:'ford', colour:'red'},
    {name:'Anna', car:'honda', colour:'green'},
    {name:'Mary', car:'bmw', colour:'red'}
];


out.find(function(item) {
    return item.name === 'John'
}

// will return the following:
{ name: 'John', car: 'bmw', colour: 'blue' }

你也可以用ES6 arrow function 为了达到同样的目的:

out.find(item => item.name === 'John')

以下是文档: Array.prototype.find()