我对JavaScript相当陌生。我正在创建一个html页面,它接受一个输入并检查该输入是否为回文。我创建了两个函数,一个用于反转字符串,另一个用于验证它是否为回文。我不确定我的职能做错了什么。我试过使用控制台进行调试,但到目前为止还没有。
这是我有的代码
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>Text Validation</title>
<script>
function reverseString(str) {
return str.toString().split("").reverse().join("");
}
function Validation() {
firstStr = document.getElementById('user')
secondStr = reverseString(firstStr)
if (firstStr == secondStr) {
alert("passed palindrome");
}
else {
alert("failed palindrome");
}
}
</script>
</head>
<body>
<table>
<tr>
<td>
<b> Enter a random word </b>
</td>
<td>
<input type="textbox" id="user">
</td>
</tr>
<td align = "right" colspan = "2">
<input type="button" id="btnSubmit" value="Submit" onClick =
"Validation();">
</td>
</table>
</body>
</html>
看起来您只需要从user
元素中提取值,如下所示:
var firstStr = document.getElementById('user').value;
下面是一个工作示例:
function reverseString(str) {
return str.toString().split("").reverse().join("");
}
function Validation() {
var firstStr = document.getElementById('user').value;
var secondStr = reverseString(firstStr)
if (firstStr == secondStr) {
alert("passed palindrome");
}
else {
alert("failed palindrome");
}
}
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>Text Validation</title>
</head>
<body>
<table>
<tr>
<td>
<b> Enter a random word </b>
</td>
<td>
<input type="textbox" id="user">
</td>
</tr>
<td align = "right" colspan = "2">
<input type="button" id="btnSubmit" value="Submit" onClick =
"Validation();">
</td>
</table>
</body>
您需要使用document.getElementById('user').value
获取值
function reverseString(str) {
return str.toString().split("").reverse().join("");
}
function Validation() {
firstStr = document.getElementById('user').value
secondStr = reverseString(firstStr)
if (firstStr == secondStr) {
alert("passed palindrome");
}
else {
alert("failed palindrome");
}
}
<table>
<tr>
<td>
<b> Enter a random word </b>
</td>
<td>
<input type="textbox" id="user">
</td>
</tr>
<td align = "right" colspan = "2">
<input type="button" id="btnSubmit" value="Submit" onClick =
"Validation();">
</td>
</table>