Question

我似乎无法深究这个问题。我有以下Javascript代码：

for(var i=0; i<links1.length; ++i) {
  console.log(links1[i]);
}
console.log(links1);

for循环的输出如下：

Object {source: 2, target: 16} 
Object {source: 32, target: 15} 
Object {source: 32, target: 31} 
Object {source: 16, target: 104} 
Object {source: 104, target: 32} 
...

虽然console.log（links1）行产生：

[Object, Object, Object, Object, Object, Object, Object, Object, Object, Object, Object, Object, Object, Object, Object, Object, Object, Object, Object, Object, Object, Object, Object, Object, Object, Object]
0: Object
source: Object
target: Object
__proto__: Object
1: Object
source: undefined
target: Object
__proto__: Object
2: Object
source: 32
target: 31
__proto__: Object
3: Object
source: 16
target: 104
__proto__: Object
4: Object
source: 104
target: 32
__proto__: Object
...

为什么在世界上我得到前两个元素的不同值？

后台没有进行AJAX调用，调用的d3.js方法是parseRows（不应该是异步）。

如果相关，代码的上下文是：

function draw_graph(nodes1, links1) {
    var width = 500;
    var height = 500;

    var force = d3.layout.force()
        .charge(-120)
        .linkDistance(30)
        .size([width, height]);

    var svg = d3.select("body").append("svg")
        .attr("width", width)
        .attr("height", height);

    console.log('tu');
    for(var i=0; i<links1.length; ++i) {
        console.log(links1[i]);
    }
    console.log(links1);
    console.log(nodes1);

    force
        .nodes(nodes1)
        .links(links1)
        .start();

    ...
}

d3.text("test1.txt", function(text) {
    var nodes = [];

    rows = d3.dsv(" ", "text/plain").parseRows(text);

    for(var i=0; i<rows.length; ++i) {
        newEl = {name:+rows[i][0], value:+rows[i][0]};
        nodes.push(newEl);
    }

    d3.text("test2.txt", function(text) {
        var links = [];

        rows = d3.dsv(" ", "text/plain").parseRows(text);

        for(var i=0; i<rows.length; ++i) {
            newEl = {source:+(rows[i][0]), target:+(rows[i][1])};
            links.push(newEl);
        }

        draw_graph(nodes, links);

    });


});

......死于

force
    .nodes(nodes1)
    .links(links1)
    .start();

使用：

Uncaught TypeError: Cannot read property 'weight' of undefined d3.js:6244
force.start d3.js:6244
draw_graph test.php:58
(anonymous function) test.php:113
(anonymous function) d3.js:1931
(anonymous function) d3.js:1916
event d3.js:434
respond

如果有人知道我做错了什么，请告诉我。

谢谢！

Javascript（d3.js） - 连续语句上的不同控制台日志输出

0 个答案: