【发布时间】：2021-04-27 18:52:57
【问题描述】：
我正在尝试计算用户开始输入和结束输入之间的时间。所以我用Date.now(); 函数命名了两个常量。每当我运行程序时，它总是给出错误：ReferenceError: start is not defined at HTMLInputElement.element.onkeyup (/main.js:86:16) 代码如下：
Javascript：
var input = document.getElementById("boch"); input.addEventListener("keyup", function (event) { if (event.keyCode === 13) { event.preventDefault(); document.getElementById("bocho").click(); } }); var element = document.querySelector("#boch"); element.onkeyup = function () { 变量值 = 元素值； if (value.includes("m")) { 让开始 = Date.now(); } if (value.includes("man")) { document.getElementById('word-1').style.backgroundColor = 'green'; } 别的 { document.getElementById('word-1').style.backgroundColor = "red"; } if (value.includes("man become")) { document.getElementById('word-2').style.backgroundColor = 'green'; } 别的 { document.getElementById('word-2').style.backgroundColor = "red"; } if (value.includes("man become as")) { document.getElementById('word-3').style.backgroundColor = 'green'; } 别的 { document.getElementById('word-3').style.backgroundColor = "red"; } if (value.includes("man become as and")) { document.getElementById('word-4').style.backgroundColor = 'green'; } 别的 { document.getElementById('word-4').style.backgroundColor = "red"; } if (value.includes("man become as and through")) { document.getElementById('word-5').style.backgroundColor = 'green'; } 别的 { document.getElementById('word-5').style.backgroundColor = "red"; } if (value.includes("man become as and through find")) { document.getElementById('word-6').style.backgroundColor = 'green'; } 别的 { document.getElementById('word-6').style.backgroundColor = "red"; } if (value.includes("man become as and through find would")) { document.getElementById('word-7').style.backgroundColor = 'green'; } 别的 { document.getElementById('word-7').style.backgroundColor = "red"; } if (value.includes("man become as and through find will here")) { document.getElementById('word-8').style.backgroundColor = 'green'; } 别的 { document.getElementById('word-8').style.backgroundColor = "red"; } if (value.includes("man become as and through find will here and")) { document.getElementById('word-9').style.backgroundColor = 'green'; } 别的 { document.getElementById('word-9').style.backgroundColor = "red"; } if (value.includes("man 通过 find will here 和 before")) { document.getElementById('word-10').style.backgroundColor = 'green'; } 别的 { document.getElementById('word-10').style.backgroundColor = "red"; } if (value.includes("man 通过 find will here 和 before")) { 让结束 = Date.now(); } 让millis =开始/结束； console.log(`经过的秒数 = ${Math.floor(millis / 1000)}`); }HTML：
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width">
<title>repl.it</title>
<link href="style.css" rel="stylesheet" type="text/css" />
</head>
<h1>
<span id="word-1">man</span> <span id="word-2">become</span> <span id="word-3">as</span>
<span id="word-4">and</span> <span id="word-5">through</span> <span id="word-6">find</span> <span id="word-7">would</span> <span id="word-8">here</span> <span id="word-9">and</span> <span id="word-10">before</span>
</h1>
<input type="text" id="boch" autocomplete="off">
</div>
<div id="typing-area">
<button id="bocho" onclick="document.getElementById('boch').value = ''">Enter</button>
</html>
<script src="main.js"></script>
【问题讨论】：
-
要么使用
var声明变量，要么将其移出if块。 -
谢谢！有效
标签： javascript html css date