Javascript語句符合所有條件可能出錯的地方

此代碼符合所有條件，請有人告訴我我哪裏出錯了;我已檢查，我不能看到任何代碼錯誤。爲什麼所有的條件都符合。Javascript語句符合所有條件可能出錯的地方

<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"; 
     } 
});

來源

2014-04-03 user3395611

沒有錯？在'if'的情況下使用賦值運算符而不是比較運算符是沒有問題的？ – Teemu

值得認真閱讀不同類型的比較操作符：

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

簡單地說，單（=），雙（==）和三（ ===）等號表示JavaScript的不同之處。

單個=是一個賦值運算符，因此在每個if語句中，您基本上都要求腳本爲變量style賦值「4-4-2」（依此類推），而不是比較這兩個值。

如果您使用==（帶有類型強制）或===（不強制），您的代碼應該可以正常工作。

來源

2014-04-03 19:10:13 BiscuitBaker

有些事情是錯的，當我把==，代碼不執行意味着沒有條件滿足。 – user3395611

@ user3395611你確定代碼中的其他部分是否設置正確？我根據你的代碼設置了一個小提琴，它的工作方式和預期的一樣：http://jsfiddle.net/QD334/ – BiscuitBaker

我的代碼中有一個空間。它現在正在工作。謝謝， – user3395611

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"; 
     }

來源

2014-04-03 18:58:41

Javascript語句符合所有條件可能出錯的地方

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