Question

下面是一些简单的代码，它采用“.somedivs”的id值，并将它们放入全局变量中，然后由条件语句排序，然后再输出到控制台。下面你可以看到我得到一些奇怪的结果，无论我使用什么条件组合，我都无法让它正常工作。看起来很基本，我在想我违反了js的某些定律，或者我错过了一些明显的东西。

  $(document).ready(function(){

    $('.somedivs').mousedown(function(){
      first = $(this).attr("id");
    }).mouseup(function(){
      second = $(this).attr("id");

      if(window.first > window.second){
        var higher = window.first;
        var lower = window.second;
        var process = 1;
      }else if(window.second > window.first){
        var higher = window.second;
        var lower = window.first;
        var process = 2;
      }else if(window.first === window.second){
        var higher = window.first;
        var lower = window.second;
        var process = 3;
      }


      if(higher > lower){
        var status = true;
      }else{
        var status = false;
      }

      console.log("process = " + process + " // " + "window.first = "+window.first+" / window.second = "+window.second + " // higher = "+higher+" / lower = "+lower + " // status = "+ status  );


    });

控制台输出，正如您可以看到的那样，如果您自己查看数字，大多数行都会返回true。我标记了箭头“＆gt;”中的一些错误。 为什么状态应为false时才为真？

process = 2 // window.first = 0 / window.second = 1 // higher = 1 / lower = 0 // status = true
process = 3 // window.first = 2 / window.second = 2 // higher = 2 / lower = 2 // status = false
process = 1 // window.first = 2 / window.second = 0 // higher = 2 / lower = 0 // status = true
> process = 1 // window.first = 5 / window.second = 22 // higher = 5 / lower = 22 // status = true
process = 3 // window.first = 7 / window.second = 7 // higher = 7 / lower = 7 // status = false
process = 2 // window.first = 3 / window.second = 9 // higher = 9 / lower = 3 // status = true
process = 1 // window.first = 19 / window.second = 14 // higher = 19 / lower = 14 // status = true
> process = 1 // window.first = 5 / window.second = 11 // higher = 5 / lower = 11 // status = true
process = 1 // window.first = 35 / window.second = 23 // higher = 35 / lower = 23 // status = true
process = 2 // window.first = 13 / window.second = 17 // higher = 17 / lower = 13 // status = true
process = 1 // window.first = 32 / window.second = 24 // higher = 32 / lower = 24 // status = true
process = 2 // window.first = 17 / window.second = 18 // higher = 18 / lower = 17 // status = true
process = 1 // window.first = 22 / window.second = 18 // higher = 22 / lower = 18 // status = true
> process = 1 // window.first = 8 / window.second = 11 // higher = 8 / lower = 11 // status = true
process = 1 // window.first = 18 / window.second = 14 // higher = 18 / lower = 14 // status = true
process = 2 // window.first = 3 / window.second = 6 // higher = 6 / lower = 3 // status = true
process = 1 // window.first = 24 / window.second = 16 // higher = 24 / lower = 16 // status = true
process = 1 // window.first = 9 / window.second = 15 // higher = 9 / lower = 15 // status = true
process = 1 // window.first = 31 / window.second = 26 // higher = 31 / lower = 26 // status = true
process = 2 // window.first = 24 / window.second = 28 // higher = 28 / lower = 24 // status = true
process = 1 // window.first = 41 / window.second = 30 // higher = 41 / lower = 30 // status = true
process = 2 // window.first = 13 / window.second = 19 // higher = 19 / lower = 13 // status = true

Answer 1

我认为这是因为变量的类型：

尝试：

first = parseInt($(this).attr("id"));

和

second = parseInt($(this).attr("id"));

Answer 2

据我所见，更高总是更高（所以状态应该总是真的）不？你总是将最高值（根据测试）影响到更高。所以除了平等（过程3），状态始终为真。

问题似乎更像是：为什么有时候更高的数字不是输出中的最高数字？

而这正是由梁良亮提出的，你在比较字符串。为了比较字符串，javascript逐字符地比较它们，例如在第一个＆gt;

中

“5”高于“22”，因为“5”高于“2”。

如果您希望您的代码使用数字值，那么您将使用Zhengliang Zheng建议的parseInt方法。

编辑：如果您希望它的状态为true或false，具体取决于哪个更高（并且您不关心更高/更低的值），那么

  var status=(parseInt(window.first)>parseInt(window.second));

应该做的伎俩

Javascript更高＆amp;较低的可变条件奇数控制台输出

2 个答案: