如何创建一个在单击时增加计数器的按钮? [英] How can I create a button that increments a counter when clicked?

问题描述

我正在尝试制作一个按钮，在单击时将计数器的值增加 1.但是，我的代码似乎不起作用.

var count = 1;var button = document.querySelector("#increment");button.addEventListener("点击", function() {var increment = document.getElementById("#count");增量值 = 计数；计数++；});

<h4>当前计数:<span id="count">0</span></h4><div class="容器"><button id="decrement">Decrement</button><button id="increment">Increment</button>

解决方案

getElementById 中不需要 # 而使用 innerHTML设定值.可以通过 id 获取时不要使用 querySelector.

像这样:

let count = 0;const button = document.getElementById("增量");const button2 = document.getElementById("递减");const textHolder = document.getElementById("count");textHolder.innerHTML = 计数；button.addEventListener("点击", function() {textHolder.innerHTML = ++count;});button2.addEventListener("点击", function() {textHolder.innerHTML = --count;});

<h4>当前计数:<span id="count">0</span></h4><div class="容器"><button id="decrement">Decrement</button><button id="increment">Increment</button>

I am trying to make a button that increments a counter's value by 1 when clicked. My code, however, doesn't seem to work.

var count = 1;
var button = document.querySelector("#increment");

button.addEventListener("click", function() {
  var increment = document.getElementById("#count");
  increment.value = count;
  count++;
});

<h4>Current count: <span id="count">0</span></h4>
<div class="container">
  <button id="decrement">Decrement</button>
  <button id="increment">Increment</button>
</div>

解决方案

You don't need # in getElementById and use innerHTML to set value. Don't use querySelector when you can get by id.

Like this:

let count = 0;
const button = document.getElementById("increment");
const button2 = document.getElementById("decrement");
const textHolder = document.getElementById("count");
textHolder.innerHTML = count;

button.addEventListener("click", function() {
  textHolder.innerHTML = ++count;
});

button2.addEventListener("click", function() {
  textHolder.innerHTML = --count;
});

<h4>Current count: <span id="count">0</span></h4>
<div class="container">
  <button id="decrement">Decrement</button>
  <button id="increment">Increment</button>
</div>

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