如何在调用函数调用次数时调用函数中的闭包

Question

我想计算单击时调用函数的次数。我有这个目前为止，但它不工作。有人能帮忙吗？

function test(){ 
    var count = (function({ 
     var i = 0; 
     return function(){ 
      return i += 1; 
     } 
    })(); 

    if(count() == 2){ 
    // do this 
    } 

} 

调用函数，就像这样：

<select onclick="javascript: test();"> 

它看起来像count函数没有正确调用。我如何调用该函数并对其执行操作？我想在某些点击次数下执行逻辑。

Answer 1

您可以使用闭包来包装呼叫。

function countUsage(methodToWrap, methodContext) { 
 
    const 
 
    wrapContext = methodContext || this; 
 
    let 
 
    count = 0; 
 
    
 
    // Return a method, this is the wrapped call. 
 
    return function methodWrapper() { 
 
    // Increase the counter by 1. 
 
    count++; 
 
    // Call the original method with the arguments. 
 
    methodToWrap.apply(wrapContext, arguments); 
 
    // Log the number of times the method was called. 
 
    console.log(`The method has been called ${count} times`); 
 
    } 
 
} 
 

 
function methodToWrap(text) { 
 
    console.log(`Log line ${text}`); 
 
} 
 

 
function sumToWrap(a, b) { 
 
    console.log(`Sum of ${a} + ${b} = ${a+b}`); 
 
} 
 

 
const 
 
    wrappedLog = countUsage(methodToWrap), 
 
    wrappedSum = countUsage(sumToWrap); 
 

 
// For these three calls you will see the count is increased with each call. 
 
wrappedLog('hello'); 
 
wrappedLog('how'); 
 
wrappedLog('are you'); 
 

 
// This will result in a log line that there has been 1 call as it is a different method. 
 
wrappedSum(3, 4);

Answer 2

这是否对你的工作？

var i = 0; 
 
    function test(){ 
 
     var count = (function() { 
 
      return function(){ 
 
       return i += 1; 
 
      } 
 
     })(); 
 
     if(count() == 2){ 
 
     console.log('reached goal') 
 
     // do this 
 
     } 
 
    
 
     alert('current count' +i) 
 
    
 
    }

<select onclick="test()"><option>select</option></select>

并在您的项目只是：

onlick="test()" 

你通常不得不在错误的地点等支架和pH值总是设置为0

Answer 3

var count = 0; 
 
function test(){ 
 
    count++; 
 
    if(count == 2){ 
 
    // do this 
 
    console.log('do something'); 
 
    } 
 
}

<label onclick="javascript: test();">Test</label>

取一个变量并增加点击次数并进行操作。