D3.js node.each()函数

node.each()函数用于评估广度一阶中每个节点的函数。在这种情况下，每个节点都被访问一次。为每个后代节点重复调用此函数。

句法：

node.each(function);

参数：此函数接受如上所述和如下所述的单个参数：

• 函数：这需要按 BFS 顺序在每个节点上调用一个函数。

返回值：此函数不返回任何内容。

示例 1：

HTML

 
 
  
 
     
     
  
    
    
 
  
 
     
    // Constructing a tree
    var tree={
            name: "rootNode",
            children: [
                {
                    name: "child1"
                },
                {
                    name: "child2",
                    children: [
                        {
                            name: "grandchild1",
                            children:[
                                {
                                    name: "grand_granchild1_1"
                                },
                                {
                                    name: "grand_granchild1_2"
                                }
                            ]
                        },
                        {
                            name: "grandchild2",
                            children:[
                                {
                                    name: "grand_granchild2_1"
                                },
                                {
                                    name: "grand_granchild2_2"
                                }
                            ]
                        },
                    ]
                }
            ]
        };
  
        var obj = d3.hierarchy(tree);
  
        const BFS = [];
          
        // Function is used
        obj.each(d => BFS.push(
            " ".repeat(d.depth) + `${d.depth}: ${d.data.name}`
            ));
  
        BFS.forEach((e)=>{
            console.log("level: ",e);
        });
     
 
  

输出：

示例 2：

HTML

 
 
  
 
     
     
  
    
    
 
  
 
     
    // Constructing a tree
    var tree={
            // Level zero
            name: "rootNode",
            children: [
                {
                    // Level one
                    name: "child1"
                },
                {
                    // Level one
                    name: "child2",
                    children: [
                        {
                            // Level two
                            name: "grandchild1",
                            children:[{
                                name: "grand_granchild1_1"
                            },
                            {
                                name: "grand_granchild1_2"
                            }]
                        }
                    ]
                },
                  
                {
                    // Level one
                    name: "child3"
                },
                {
                    // Level one
                    name: "child4"
                }
            ]
        };
  
        var obj = d3.hierarchy(tree);
  
        const BFS = [];
        
        // Function is used
        obj.each(d => BFS.push(
            " ".repeat(d.depth) 
                + `${d.depth}: ${d.data.name}`
        ));
  
        console.log(BFS);
     
 
  

输出：