块级作用域
2018-12-21 本文已影响0人
asmuzi
块级作用域
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Document</title>
<script>
if (12 > 5) {
var a = 12;
}
console.log(a);
</script>
</head>
<body>
</body>
</html>
块级作用域2
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Document</title>
<script>
window.onload = function () {
let aBtn = document.getElementsByTagName('input');
for (let i = 0; i < aBtn.length; i++) {
aBtn[i].onclick = function () {
console.log(i);
};
}
};
</script>
</head>
<body>
<div>
<input type="button" value="a">
<input type="button" value="b">
<input type="button" value="c">
</div>
</body>
</html>
