Javascript，点击按钮增加计数器 [英] Javascript, increment a counter on button click

问题描述

在javascript中，我要创建一个计数器，以在单击按钮时增加该值。

In javascript, I want to make a counter that increases the value when you click a button.

当我第一次单击添加按钮时，该数字并没有增加。

When I click the add button the first time, the number doesn't increase.

但是当我将值打印到控制台时，结果会增加。

But when I print the value to the console, the result increases.

小提琴： http://jsfiddle.net/techydude/H63As/

  $(function() {
    var //valueCount = $("counter").value(),
        counter = $("#counter"),
        addBtn = $("#add"),
        value = $("#counter").html();

      addBtn.on("click", function() {

      counter.html(value ++);  //this value is not incremented.
      console.log(value);      //this value gets incremented.
      return

    });

  });​

如何使两行的值都显示相同？

How do I make the value show the same for both lines?

推荐答案

您正在执行发布增量。使其预先递增：

You are doing a Post Increment. Make it pre-increment:

addBtn.on("click", function() {
  counter.html(++value);
  console.log(value);
  return
});

说明：

Explanation:

// Increment operators
x = 1;
y = ++x;    // x is now 2, y is also 2
y = x++;    // x is now 3, y is 2

// Decrement operators
x = 3;
y = x--;    // x is now 2, y is 3
y = --x;    // x is now 1, y is also 1

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