我對JavaScript很新穎,想要編寫html網站的標題。 JS:當窗口寬度小於1215px - >左側部分寬度爲100%時;右側部分的標題爲0JS - 無法讀取屬性'setAttribute'爲空
我總是得到「無法讀取屬性'setAttribute'爲null」錯誤!
請幫忙! 代碼:
if (window.innerWidth < 1215) {
document.getElementById("#headerLeft").setAttribute("style", "width:100%");
document.getElementById("#headerRight").setAttribute("style", "width:0%");
} else {
document.getElementById("#headerLeft").setAttribute("style", "width:50%");
document.getElementById("#headerRight").setAttribute("style", "width:50%");
}
body {
margin:0;
}
header{
height:100px;
width:100%;
}
#headerLeft {
background-color:#FF7043;
height:100px;
float:left;
}
#headerRight {
background-color:#FFFFFF;
height:100px;
float:right;
}
.headerTitle {
font-family:'Roboto', sans-serif;
margin:15px;
font-size:70px;
}
#headerRight .headerTitle {
text-align:left;
color:#FF7043;
font-weight:300;
}
#headerLeft .headerTitle {
text-align:center;
color:#FFFFFF;
font-weight:900;
}
<!doctype html>
<html>
<head>
<meta charset="UTF-8">
<title>example</title>
<!-- css -->
<link type="text/css" rel="stylesheet" href="style.css">
<!-- fonts -->
<link href='https://fonts.googleapis.com/css?family=Roboto:400,500,700,900,100,300' rel='stylesheet' type='text/css'>
<!-- javascripts -->
<script language="javascript" type="text/javascript" src="script.js"></script>
</head>
<body>
<header>
<div id="headerLeft">
<p class="headerTitle">example</p>
</div>
<div id="headerRight">
<p class="headerTitle">example</p>
</div>
</header>
<nav>
</nav>
<main>
</main>
<footer>
</footer>
</body>
</html>
不回答你的問題,但你可能想看看[媒體查詢(https://developer.mozilla.org/en- US/docs/Web/CSS/Media_Queries/Using_media_queries) –