我想通过JS打印出“This is the first/second/third paragraph.”三行，然而出现问题
以下是我的代码
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<style>
</style>
</head>
<body>
<div>
<button>BUTTON</button>
</div>
<script>
// 设想制作一个映射表
/* +-------------+--------+
| IndexNumber | Value |
+-------------+--------+
| 0 | first |
| 1 | second |
| 2 | third |
| 3 | fourth |
| 4 | fifth |
+-------------+--------+ */
for (let i = 0; i < 3; ++i) {
switch (i) {
case 0:
i = 'first';
break;
case 1:
i = 'second';
break;
case 2:
i = 'third';
break;
case 3:
i = 'fourth';
break;
case 4:
i = 'fifth';
break;
}
document.getElementsByTagName('div')[0].innerHTML += "This is the " + i + " paragraph.<br/>";
}
</script>
</body>
</html>
以下是结果，只打印出了 “This is the first paragraph.”
求各位指点！
i被你的first覆盖了。后续做for循环判断被判断为退出循环了
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<style>
</style>
</head>
<body>
<div>
<button>BUTTON</button>
</div>
<script>
// 设想制作一个映射表
/* +-------------+--------+
| IndexNumber | Value |
+-------------+--------+
| 0 | first |
| 1 | second |
| 2 | third |
| 3 | fourth |
| 4 | fifth |
+-------------+--------+ */
for (let i = 0; i < 3; ++i) {
let mText
switch (i) {
case 0:
mText = 'first';
break;
case 1:
mText = 'second';
break;
case 2:
mText = 'third';
break;
case 3:
mText = 'fourth';
break;
case 4:
mText = 'fifth';
break;
}
document.getElementsByTagName('div')[0].innerHTML += "This is the " + mText + " paragraph.<br/>";
}
</script>
</body>
</html>
不是i++吗？还有i<3，i最多等于2