Question

此代码符合所有条件，有人请告诉我哪里出错了;我检查过，我看不出代码有什么问题。为什么满足所有条件。

<script>
$( document ).ready(function() {
    var style = $('#el_teams_TeamFormation span').html(); 
    alert (style);
         if (style = "4-4-2")
          { 
            document.getElementById('footballpitch1').style.display = "none";
            document.getElementById('footballpitch2').style.display = "none";
            document.getElementById('footballpitch3').style.display = "none";
            document.getElementById('footballpitch4').style.display = "none";
            document.getElementById('footballpitch1').style.display = "block";
         }
         if (style = "3-4-3")
          {
            document.getElementById('footballpitch1').style.display = "none";
            document.getElementById('footballpitch2').style.display = "none";
            document.getElementById('footballpitch3').style.display = "none";
            document.getElementById('footballpitch4').style.display = "none";
            document.getElementById('footballpitch2').style.display = "block";
         } 
         if (style = "3-5-2") {
            document.getElementById('footballpitch1').style.display = "none";
            document.getElementById('footballpitch2').style.display = "none";
            document.getElementById('footballpitch3').style.display = "none";
            document.getElementById('footballpitch4').style.display = "none";
            document.getElementById('footballpitch3').style.display = "block";
         }
         if (style = "4-5-1") {
            document.getElementById('footballpitch1').style.display = "none";
            document.getElementById('footballpitch2').style.display = "none";
            document.getElementById('footballpitch3').style.display = "none";
            document.getElementById('footballpitch4').style.display = "none";
            document.getElementById('footballpitch4').style.display = "block";
         }
});

Answer 1

值得熟悉不同类型的比较运算符：

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Comparison_Operators

简单地说，单个（=），双（==）和三个（===）等于符号，每个符号都表示不同的JavaScript。

单个=是赋值运算符，因此在每个if语句中，您实际上都要求脚本为变量{赋值“4-4-2”（依此类推） {1}}而不是比较这两个值。

如果您使用style（带有类型强制）或==（没有强制），您的代码应该可以正常使用。

Answer 2

if (style == "4-4-2")
          { 
            document.getElementById('footballpitch1').style.display = "none";
            document.getElementById('footballpitch2').style.display = "none";
            document.getElementById('footballpitch3').style.display = "none";
            document.getElementById('footballpitch4').style.display = "none";
            document.getElementById('footballpitch1').style.display = "block";
         }
         if (style == "3-4-3")
          {
            document.getElementById('footballpitch1').style.display = "none";
            document.getElementById('footballpitch2').style.display = "none";
            document.getElementById('footballpitch3').style.display = "none";
            document.getElementById('footballpitch4').style.display = "none";
            document.getElementById('footballpitch2').style.display = "block";
         } 
         if (style == "3-5-2") {
            document.getElementById('footballpitch1').style.display = "none";
            document.getElementById('footballpitch2').style.display = "none";
            document.getElementById('footballpitch3').style.display = "none";
            document.getElementById('footballpitch4').style.display = "none";
            document.getElementById('footballpitch3').style.display = "block";
         }
         if (style == "4-5-1") {
            document.getElementById('footballpitch1').style.display = "none";
            document.getElementById('footballpitch2').style.display = "none";
            document.getElementById('footballpitch3').style.display = "none";
            document.getElementById('footballpitch4').style.display = "none";
            document.getElementById('footballpitch4').style.display = "block";
         }

Javascript语句符合所有可能出错的条件

2 个答案: