Question

 $('#toggle-linecolor').click(function () {
        chart.yAxis[0].update({
            lineColor: lineColor
        });
        lineColor = { red: 'blue', blue: 'red' }[lineColor];
    });

Answer 1

它在'red'和'blue'之间切换。

鉴于你开始：

var lineColor = 'red';

执行此操作会将lineColor更改为“蓝色”

lineColor = { red: 'blue', blue: 'red' }[lineColor];
// The property [red] of that object has a value of 'blue'

lineColor // <--- 'blue'

再次执行它，它会将值切换为'red'

lineColor = { red: 'blue', blue: 'red' }[lineColor];
// The property [blue] of that object has a value of 'red'

lineColor // <---- 'red'

Answer 2

它交换/切换颜色。红色 - ＆gt;蓝色，蓝色 - ＆gt;红色

lineColor = 'blue';
lineColor = { red: 'red', blue: 'blue' }[lineColor]; // 'red'

与

相同

lineColor = { red: 'red', blue: 'blue' }.blue; // 'red'

Answer 3

这是一种巧妙的方式来实现切换作为一个班轮。你可以像这样解压缩它：

var lineColor = 'red';
function toggleColor(){
    chart.yAxis[0].update({
        lineColor: lineColor
    });
    var opposites = { red : 'blue', blue : 'red' };
    if( lineColor == 'red' ){
        lineColor = opposites.red; // assigns 'blue' to lineColor
    }
    else if( lineColor == 'blue' ){
        lineColor = opposites.blue; // assigns 'red' to lineColor
    }

    // but you can shorten the above if/else statement to:
    lineColor = opposites[ lineColor ];

    // which can be shortened to this if you don't want to 
    // assign the opposites object to a variable:
    lineColor = { red: 'blue', blue: 'red' }[lineColor];
}

编辑注释：您可以使用两种以上的颜色创建循环序列：

opposites = { red : 'green', green : 'yellow', yellow : 'blue', blue : 'red' };

所以如果当前颜色为红色变为绿色，如果绿色变为黄色，如果黄色变为蓝色，如果变为蓝色变为红色：http://jsfiddle.net/p3bw04vw/

这是什么意思var lineColor = {red：'blue'，blue：'red'} [lineColor];

3 个答案: