1 //定义一个源数组
2 var dataList = ["tiger", "dragon", "snake", "horse", "sheep"];
3 //构建一个集合，将其保存在变量set中
4 var set = d3.set(dataList);
5
6
7 console.log(set.has("tiger")) //返回值true
8 console.log(set.add("monkey")) //返回值monkey
9
10 console.log(set.values()) //返回值["tiger", "dragon", "snake", "horse", "sheep", "monkey"]
11
12 //集合中的每一个元素都将调用function函数
13 set.forEach(function(value){
14 console.log(value) //返回值分别打印出tiger、dragon、snake、horse、sheep、monkey
15 })
16
17 console.log(set.empty()) //返回值false
18 console.log(set.size()) //返回值6
1 var dataList = ["tiger","tiger", "dragon", "snake", "horse", "sheep"];
2 var set = d3.set(dataList);
3 set.add("dragon");
4
5 console.log(set.values()) //返回值 ["tiger", "dragon", "snake", "horse", "sheep"]
D3.js的基础部分之数组的处理 集合(Set)(v3版本)
原文：https://www.cnblogs.com/littleSpill/p/10812779.html