jQuery callbacks.empty() 方法

jQuery 中的callbacks.empty() 方法用于从列表中删除所有回调。它返回它所附加的回调对象。

句法：

callbacks.empty()

参数：它不接受任何参数。

返回值：此方法返回它所附加的回调对象。

下面的例子说明了 jQuery 中的callbacks.empty() 方法：

示例 1：在此示例中，首先将fun1函数添加到回调列表中，并使用给定参数在列表中执行所有存在的回调。执行callbacks.empty()方法以清空列表。添加第二个函数fun2并再次执行回调列表。这演示了添加第一个函数后清空列表。

html

  

    
        JQuery callbacks.empty() method
    
  
    
    

  

  
    
        GeeksForGeeks
    
  
    
        JQuery | callbacks.empty() method
    
  
    
        click here
    
  
    
  
    
        var output = document.getElementById("output");
        var res = "";
  
        // Initialize a callback list
        var callbacks = jQuery.Callbacks();
  
        function Geeks() {
              
            // First function to be added to the list
            var fun1 = function (val) {
                res = res + "This is function 1 and" +
                    " value passed is " + val + "<br>";
            };
  
            // Second function to be added to the list
            var fun2 = function (val) {
                res = res + "This is function 2 and" +
                    " value passed is " + val + "<br>";
            };
  
            // Adding the first function
            callbacks.add(fun1);
  
            // Calling the first function
            callbacks.fire("GFG_1");
  
            // Clearing the callback list
            callbacks.empty();
  
            // Adding the second function
            callbacks.add(fun2);
  
            // Calling the first function
            callbacks.fire("GFG_2");
  
            output.innerHTML = res;
        } 
    

  

输出：

示例 2：此示例提供了一个按钮来清空回调列表，然后添加给定的函数以查看清空回调列表的结果。

html

  

    
        JQuery | callbacks.empty() method
    
  
    
    

  

  
    
        GeeksForGeeks
    
  
    
        JQuery | callbacks.empty() method
    
  
    
        click here
    
  
    
        empty
    
      
    
  
    
        var output = document.getElementById("output");
        var res = "";
  
        // Initialize a callback list
        var callbacks = jQuery.Callbacks();
  
        function empty() {
  
            // Clear the callback list
            callbacks.empty();
        }
  
        // Function to add and fire callbacks 
        function Geeks() {
  
            // Function to be added to the list
            var fun1 = function (val) {
                res = res + "This is function 1 and" +
                    " value passed is " + val + "<br>";
            };
  
            // Adding the given function
            callbacks.add(fun1);
  
            // Calling the function with value
            callbacks.fire("GFG_1");
  
            output.innerHTML = res;
        } 
    

  

输出：