javascript关闭不能正常工作 [英] javascript closure not working as it should

问题描述

查看第一个代码：

 var count = 0;
 (function addLinks() {
   var count = 0;//this count var is increasing

   for (var i = 0, link; i < 5; i++) {
     link = document.createElement("a");
     link.innerHTML = "Link " + i;

     link.onclick = function () {
       count++;
       alert(count);
     };

     document.body.appendChild(link);
   }
 })();

点击链接后，每个链接元素的计数器变量都会继续增加。这是预期的结果。

When the link gets clicked the counter variable keeps on increasing for each link element. This is the expected result.

第二：

var count = 0;
$("p").each(function () {
  var $thisParagraph = $(this);
  var count = 0;//this count var is increasing too.so what is different between them .They both are declared within the scope in which closure was declared

  $thisParagraph.click(function () {
    count++;
    $thisParagraph.find("span").text('clicks: ' + count);
    $thisParagraph.toggleClass("highlight", count % 3 == 0);
  });
});

此处闭包功能未按预期工作。每次点击段落元素时，计数器 var 都会增加，但点击第二段元素时不显示该增量？这是什么原因？为什么会这样？每个段落元素的count变量都没有增加。

Here the closure function is not working as expected. On each click on the paragraph element, the counter var is increased but that increment is not displayed on click on second paragraph element? What is the reason for this? Why is this happening? The count variable is not increasing for each paragraph element.

推荐答案

你的意思是：

var count = 0;
$("p").each(function() {
   var $thisParagraph = $(this);
   //var count = 0; //removed this count, as it re-inits count to 0
   $thisParagraph.click(function() {
   count++;
   $thisParagraph.find("span").text('clicks: ' + count);
   $thisParagraph.toggleClass("highlight", count % 3 == 0);
  });
});

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