原型 - hasClassName() 方法

此方法檢查元素是否擁有給定的 CSS className。

語法

element.hasClassName( className );

返回值

如果元素擁有給定的類名則返回 true，否則返回 false。

示例

<html>
   <head>
      <title>Prototype examples</title>
      <script type = "text/javascript" src = "/javascript/prototype.js"></script>
      
      <script>
         function showResult() {
            if( $('grandfather').hasClassName("test") ) {
               alert("Grandfather has CSS test class.");
            }
            if( $('father').hasClassName("test") ) {
               alert("Father has CSS test class.");
            }
            if( $('kid').hasClassName("test") ) {
               alert("Kid has CSS test class.");
            }
         }
      </script>
      
      <style>
         .test {
            font-size: 12px;
            margin-left: 1em;
         }
      </style>
   </head>

   <body>
      <p>Click the button to see the result.</p>
      
      <div id = "grandfather" class = "test">This is grand father
         <div id = "father"> This is father.
            <div id = "kid" class = "test">This is kid</div>
         </div>
      </div>
      <br />
      
      <input type = "button" value = "showResult" onclick = "showResult();"/>
   </body>
</html>

輸出

prototype_element_object.htm

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