javascript - 为什么我无法获取表单中输入的值

Question

我在页脚中有一个表单，现在我只想记录名称字段的值。我通过在查询选择器末尾添加 .value 属性来实现此目的。不幸的是，这不起作用。

我的 JS 看起来像这样

submit.addEventListener('click', function(e) {
    e.preventDefault();
    let name = document.querySelector('#name').value;
    console.log(name);
})

由于某种原因，我得到一个空字符串。任何想法

const navLinks = document.querySelectorAll('.nav-links .link');
const linksArray = Array.from(document.querySelectorAll('.links div'));
const header = document.querySelector('header');
const submit = document.querySelector('#submit');


for (var i = 0; i < navLinks.length; i++) {
	navLinks[i].addEventListener('click', changeColor);
}

for (var i = 0; i < linksArray.length; i++) {
	linksArray[i].addEventListener('click', shuffle);
}

function changeColor() {
	let hexArray = [0, 1, 2, 3, 4, 5, 6, 'A', 'B', 'C', 'D', 'E', 'F'];
	let hexColor = '#';

	for(let i = 0; i < 6; i++) {
		let random = Math.floor(Math.random()*hexArray.length);
		hexColor += hexArray[random];
	}

	header.style.background = hexColor;

	setTimeout(function() {
		header.style.backgroundImage = 'url(img/canada.jpeg)';
	}, 2000);
}

function shuffle() { //  Fisher-Yates shuffle algorithm
  for (let i = linksArray.length - 1; i > 0; i--) {
    let j = Math.floor(Math.random() * (i + 1)); 
    [linksArray[i].innerHTML, linksArray[j].innerHTML] = [linksArray[j].innerHTML, linksArray[i].innerHTML]; 
  }
}

submit.addEventListener('click', function(e) {
	e.preventDefault();
	let name = document.querySelector('#name').value;
	console.log(name);
})

html, body {
	margin: 0;
	padding: 0;
}

body {
	font-family: 'Verdana';
	box-sizing: border-box;
	color: #63889b;
}
/*
* {
	outline: 1px solid red;
}*/

/*------NAV-----*/

nav {
	display: flex;
	justify-content: space-between;
	font-size: 1.8rem;
	padding: 25px 0;
	position: fixed;
	background-color: #fff;
	width: 100%;
	top: 0;
	left: 0;
	right: 0;
	z-index: 10;
}

.brand, .nav-links {
	display: flex;
	align-items: center;
}

.brand {
	margin-left: 6%;
}

.logo {
	max-width: 70px;
	max-height: 45px;
	margin-right: 25px;
}

.nav-links {
	position: relative;
	margin-right: 6%;
}

.nav-links .link {
	text-transform: uppercase;
	margin-right: 20px;
	cursor: pointer;
	transition: all .2s ease;
}

.nav-links .link:hover {
	color: #014263;
}

/*-----HEADER-----*/

header {
	margin-top: 92px;
	background-image: url(img/canada.jpeg);
	/*background-position: center;
	background-size: cover;*/
	padding-top: 7%;
	padding-bottom: 25%;
}

.header-info {
	color: #fff;
	font-size: 1.5rem;
	width: 22.5%;
	background-color: rgba(0,0,0,0.6);
	padding: 35px;
	margin-left: 10%;
}

header p {
	margin: 0;
	padding: 0;
}

header p:first-child {
	margin-bottom: 25px;
}


/*-----MAIN-----*/

main {
	display: flex;
	background-color: #fff;

}

.col {
	flex-basis: 33.33%;
	padding: 50px 0;
}

.col p {
	width: 65%;
	font-size: 1.25rem;
	text-align: center;
	margin-left: auto;
	margin-right: auto;
}

.col img {
	display: block;
	margin: 0 auto;
}

.col-3 img {
	width: 280px;
	height: 155px;
}

.col-3 img, .col-3 h3, .col-3 p {
	position: relative;
	top: -8px;
}

.col-2 img, .col-2 h3, .col-2 p {
	position: relative;
	top: 30px;
}

.col-1 {
	margin-left: 7%;
}

.col-3 {
	margin-right: 7%;
}

h3 {
	text-align: center;
}

/*------FOOTER-----*/

footer {
	font-family: 'Helvetica';
	background-color: #63889b;
	display: flex;
	justify-content: space-between;
	color: #fff;
	padding-bottom: 30px;
}

.internal-links {
	padding-left: 15%;
	font-size: 1.5rem;
}

.links div {
	margin:2px 0;
	cursor: pointer;
}

.internal-links h4 {
	text-decoration: underline;
	text-align: center;
	margin-bottom: 8px;
	margin-top: 30PX;
	color: #fff;
}

.links {
	font-size: 1.2rem; 
	display: flex;
	flex-direction: column;
}

.form-wrap {
	padding-top: 30px;
	display: flex;
	align-items: flex-end;
	flex-basis: 50%;
}

form {
	margin: 0 100px 0 0;
	display: flex;
	flex-direction: column;
	width: 100%;
}

input {
	border: none;
	outline: none;
	font-size: 1.6rem;
}

label {
	font-size: 1.3rem;
	padding: 3px 0;
}

button {
	margin-top: 20px;
	border: 1px solid #fff;
	width: 50%;
	font-size: 1.3rem;
	background-color: #1090d1;
	align-self: flex-end;
	color: #fff;
	padding: 4px 30px;
}

/*.dialog-wrap {
	background-color: rgba(0,0,0,0.7);
	position: fixed;
    width: 100%;
    height: 100%;
    top: 0px;
    left: 0px;
    z-index: 1000;
}*/

/*dialog {
	position: fixed;
	top: 0;
	left: 0;
	right: 0;
	bottom: 0;
	width: 500px;
	height: 215px;
	border: none;
	display: flex;
	flex-direction: column;
	justify-content: flex-start;
}

dialog div {
	font-size: 1.4rem;
	color: #fff;
	margin: 10px 0;
	outline: 1px solid #63889b;
}

dialog div:first-child {
	margin-top: 0px;
}

dialog .label {
	background-color: #63889b;
	padding: 7px;
	display: inline-block;
	width: 30%;
	margin: 0;
	text-align: center;
}

dialog .info {
	display: inline-block;
}

dialog .buttons {
	outline: none;
	display: flex;
	justify-content: space-between;

}

dialog button {
	border: none;
	width: 49%;
	margin: 0;
}*/

<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>Chapman Automotive Skills Assessment</title>
	<link rel="stylesheet" href="style.css">
</head>
<body>
	<nav>
		<div class="brand">
		<img src="img/Logo.png" alt="logo" class="logo">
		<div class="comp-name">CHAPMAN</div>
		</div>

		<div class="nav-links">
			<div class="link">Home</div>
			<div class="link">Sales</div>
			<div class="link">Blog</div>
			<div class="link">Login</div>
		</div>
	</nav>
	<header>
		<div class="header-info">
			<p>We are a company that does stuff.</p>
			<p>Car and web stuff.</p>
		</div>
	</header>
	<main>
		<div class="col col-1">
			<img src="img/car1.jpg" alt="car1">

			<h3>Some Header</h3>

			<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Explicabo tempore quia enim quod, perferendis illum quae id, natus dolores temporibus. Lorem ipsum dolor sit amet, consectetur adipisicing elit. Obcaecati, rem. Lorem ipsum dolor sit amet, consectetur adipisicing elit. Necessitatibus tenetur mollitia officiis laudantium dolore ipsa.</p>
		</div>

		<div class="col col-2">
			<img src="img/car2.jpg" alt="car2">

			<h3>More Stuff</h3>

			<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Explicabo tempore quia enim quod, perferendis illum quae id, natus dolores temporibus. Lorem ipsum dolor sit amet, consectetur adipisicing elit. Illo, dolor. Lorem ipsum dolor sit amet, consectetur adipisicing elit. Perspiciatis, neque. Corporis quisquam eligendi libero omnis.</p>
		</div>

		<div class="col col-3">
			<img src="img/car3.jpg" alt="car3">

			<h3>Last Column</h3>

			<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Explicabo tempore quia enim quod, perferendis illum quae id, natus dolores temporibus. Lorem ipsum dolor sit amet, consectetur adipisicing elit. Esse, ipsa. Lorem ipsum dolor sit amet, consectetur adipisicing elit. Quod quae, nihil error delectus voluptatum deserunt.</p>
		</div>
	</main>
	<footer id="footer">
		<div class="internal-links">
			<h4>Internal Links</h4>

			<div class="links">
				<div>Page One</div>
				<div>Another Page</div>
				<div>Sales Page</div>
				<div>Page Three</div>
				<div>Keep Going</div>
				<div>Last One</div>
				<div>Just Kidding</div>
			</div>
		</div>

		<div class="form-wrap">
			<form>
				<label for="Name">Name</label>
				<input type="text" id="Name" required>
				<label for="Name">Address</label>
				<input type="text" id="Address" required>
				<label for="Name">City</label>
				<input type="text" id="City" required>

				<button type="submit" id="submit">Submit Form</button>
				</form>

				<div class="dialog-wrap">
					<dialog>
						<div><span class="label">Name:</span><input type="text" class="info"></div>
						<div><span class="label">Address:</span><input type="text" class="info"></div>
						<div><span class="label">City:</span><input type="text" class="info"></div>
						<div class="buttons"><button>Edit</button><button>Correct</button></div>
					</dialog>
				</div>
	</footer>
	<script src="script.js"></script>
</body>
</html>

Answer 1

您没有得到空字符串，而是抛出 TypeError: Cannot read property 'value' of null 错误，因为元素的 id 是“Name”，而您的查询选择器是 '#name'(而不是“Name”)。

这是您的代码的工作版本:

const navLinks = document.querySelectorAll('.nav-links .link');
const linksArray = Array.from(document.querySelectorAll('.links div'));
const header = document.querySelector('header');
const submit = document.querySelector('#submit');


for (var i = 0; i < navLinks.length; i++) {
	navLinks[i].addEventListener('click', changeColor);
}

for (var i = 0; i < linksArray.length; i++) {
	linksArray[i].addEventListener('click', shuffle);
}

function changeColor() {
	let hexArray = [0, 1, 2, 3, 4, 5, 6, 'A', 'B', 'C', 'D', 'E', 'F'];
	let hexColor = '#';

	for(let i = 0; i < 6; i++) {
		let random = Math.floor(Math.random()*hexArray.length);
		hexColor += hexArray[random];
	}

	header.style.background = hexColor;

	setTimeout(function() {
		header.style.backgroundImage = 'url(img/canada.jpeg)';
	}, 2000);
}

function shuffle() { //  Fisher-Yates shuffle algorithm
  for (let i = linksArray.length - 1; i > 0; i--) {
    let j = Math.floor(Math.random() * (i + 1)); 
    [linksArray[i].innerHTML, linksArray[j].innerHTML] = [linksArray[j].innerHTML, linksArray[i].innerHTML]; 
  }
}

submit.addEventListener('click', function(e) {
	e.preventDefault();
	let name = document.querySelector('#Name').value;
	console.log(name);
})

html, body {
	margin: 0;
	padding: 0;
}

body {
	font-family: 'Verdana';
	box-sizing: border-box;
	color: #63889b;
}
/*
* {
	outline: 1px solid red;
}*/

/*------NAV-----*/

nav {
	display: flex;
	justify-content: space-between;
	font-size: 1.8rem;
	padding: 25px 0;
	position: fixed;
	background-color: #fff;
	width: 100%;
	top: 0;
	left: 0;
	right: 0;
	z-index: 10;
}

.brand, .nav-links {
	display: flex;
	align-items: center;
}

.brand {
	margin-left: 6%;
}

.logo {
	max-width: 70px;
	max-height: 45px;
	margin-right: 25px;
}

.nav-links {
	position: relative;
	margin-right: 6%;
}

.nav-links .link {
	text-transform: uppercase;
	margin-right: 20px;
	cursor: pointer;
	transition: all .2s ease;
}

.nav-links .link:hover {
	color: #014263;
}

/*-----HEADER-----*/

header {
	margin-top: 92px;
	background-image: url(img/canada.jpeg);
	/*background-position: center;
	background-size: cover;*/
	padding-top: 7%;
	padding-bottom: 25%;
}

.header-info {
	color: #fff;
	font-size: 1.5rem;
	width: 22.5%;
	background-color: rgba(0,0,0,0.6);
	padding: 35px;
	margin-left: 10%;
}

header p {
	margin: 0;
	padding: 0;
}

header p:first-child {
	margin-bottom: 25px;
}


/*-----MAIN-----*/

main {
	display: flex;
	background-color: #fff;

}

.col {
	flex-basis: 33.33%;
	padding: 50px 0;
}

.col p {
	width: 65%;
	font-size: 1.25rem;
	text-align: center;
	margin-left: auto;
	margin-right: auto;
}

.col img {
	display: block;
	margin: 0 auto;
}

.col-3 img {
	width: 280px;
	height: 155px;
}

.col-3 img, .col-3 h3, .col-3 p {
	position: relative;
	top: -8px;
}

.col-2 img, .col-2 h3, .col-2 p {
	position: relative;
	top: 30px;
}

.col-1 {
	margin-left: 7%;
}

.col-3 {
	margin-right: 7%;
}

h3 {
	text-align: center;
}

/*------FOOTER-----*/

footer {
	font-family: 'Helvetica';
	background-color: #63889b;
	display: flex;
	justify-content: space-between;
	color: #fff;
	padding-bottom: 30px;
}

.internal-links {
	padding-left: 15%;
	font-size: 1.5rem;
}

.links div {
	margin:2px 0;
	cursor: pointer;
}

.internal-links h4 {
	text-decoration: underline;
	text-align: center;
	margin-bottom: 8px;
	margin-top: 30PX;
	color: #fff;
}

.links {
	font-size: 1.2rem; 
	display: flex;
	flex-direction: column;
}

.form-wrap {
	padding-top: 30px;
	display: flex;
	align-items: flex-end;
	flex-basis: 50%;
}

form {
	margin: 0 100px 0 0;
	display: flex;
	flex-direction: column;
	width: 100%;
}

input {
	border: none;
	outline: none;
	font-size: 1.6rem;
}

label {
	font-size: 1.3rem;
	padding: 3px 0;
}

button {
	margin-top: 20px;
	border: 1px solid #fff;
	width: 50%;
	font-size: 1.3rem;
	background-color: #1090d1;
	align-self: flex-end;
	color: #fff;
	padding: 4px 30px;
}

/*.dialog-wrap {
	background-color: rgba(0,0,0,0.7);
	position: fixed;
    width: 100%;
    height: 100%;
    top: 0px;
    left: 0px;
    z-index: 1000;
}*/

/*dialog {
	position: fixed;
	top: 0;
	left: 0;
	right: 0;
	bottom: 0;
	width: 500px;
	height: 215px;
	border: none;
	display: flex;
	flex-direction: column;
	justify-content: flex-start;
}

dialog div {
	font-size: 1.4rem;
	color: #fff;
	margin: 10px 0;
	outline: 1px solid #63889b;
}

dialog div:first-child {
	margin-top: 0px;
}

dialog .label {
	background-color: #63889b;
	padding: 7px;
	display: inline-block;
	width: 30%;
	margin: 0;
	text-align: center;
}

dialog .info {
	display: inline-block;
}

dialog .buttons {
	outline: none;
	display: flex;
	justify-content: space-between;

}

dialog button {
	border: none;
	width: 49%;
	margin: 0;
}*/

<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>Chapman Automotive Skills Assessment</title>
	<link rel="stylesheet" href="style.css">
</head>
<body>
	<nav>
		<div class="brand">
		<img src="img/Logo.png" alt="logo" class="logo">
		<div class="comp-name">CHAPMAN</div>
		</div>

		<div class="nav-links">
			<div class="link">Home</div>
			<div class="link">Sales</div>
			<div class="link">Blog</div>
			<div class="link">Login</div>
		</div>
	</nav>
	<header>
		<div class="header-info">
			<p>We are a company that does stuff.</p>
			<p>Car and web stuff.</p>
		</div>
	</header>
	<main>
		<div class="col col-1">
			<img src="img/car1.jpg" alt="car1">

			<h3>Some Header</h3>

			<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Explicabo tempore quia enim quod, perferendis illum quae id, natus dolores temporibus. Lorem ipsum dolor sit amet, consectetur adipisicing elit. Obcaecati, rem. Lorem ipsum dolor sit amet, consectetur adipisicing elit. Necessitatibus tenetur mollitia officiis laudantium dolore ipsa.</p>
		</div>

		<div class="col col-2">
			<img src="img/car2.jpg" alt="car2">

			<h3>More Stuff</h3>

			<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Explicabo tempore quia enim quod, perferendis illum quae id, natus dolores temporibus. Lorem ipsum dolor sit amet, consectetur adipisicing elit. Illo, dolor. Lorem ipsum dolor sit amet, consectetur adipisicing elit. Perspiciatis, neque. Corporis quisquam eligendi libero omnis.</p>
		</div>

		<div class="col col-3">
			<img src="img/car3.jpg" alt="car3">

			<h3>Last Column</h3>

			<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Explicabo tempore quia enim quod, perferendis illum quae id, natus dolores temporibus. Lorem ipsum dolor sit amet, consectetur adipisicing elit. Esse, ipsa. Lorem ipsum dolor sit amet, consectetur adipisicing elit. Quod quae, nihil error delectus voluptatum deserunt.</p>
		</div>
	</main>
	<footer id="footer">
		<div class="internal-links">
			<h4>Internal Links</h4>

			<div class="links">
				<div>Page One</div>
				<div>Another Page</div>
				<div>Sales Page</div>
				<div>Page Three</div>
				<div>Keep Going</div>
				<div>Last One</div>
				<div>Just Kidding</div>
			</div>
		</div>

		<div class="form-wrap">
			<form>
				<label for="Name">Name</label>
				<input type="text" id="Name" required>
				<label for="Name">Address</label>
				<input type="text" id="Address" required>
				<label for="Name">City</label>
				<input type="text" id="City" required>

				<button type="submit" id="submit">Submit Form</button>
				</form>

				<div class="dialog-wrap">
					<dialog>
						<div><span class="label">Name:</span><input type="text" class="info"></div>
						<div><span class="label">Address:</span><input type="text" class="info"></div>
						<div><span class="label">City:</span><input type="text" class="info"></div>
						<div class="buttons"><button>Edit</button><button>Correct</button></div>
					</dialog>
				</div>
	</footer>
	<script src="script.js"></script>
</body>
</html>