javascript 闭包无法正常工作

Question

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);
   }
 })();

当链接被单击时，每个链接元素的计数器变量不断增加。这是预期的结果。

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);
  });
});

这里的闭包函数没有按预期工作。每次单击段落元素时，计数器 var 都会增加，但单击第二个段落元素时不会显示该增量？这是什么原因呢？为什么会发生这种情况？每个段落元素的计数变量不会增加。

Answer 1

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);
  });
});