如何使用外部 javascript 验证表单值
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how to validate form values using external javascript
提问by
Here I have created two fields one is for first name and another is for last name. Now how can I access these fields in external Javascript file and validate them.
在这里，我创建了两个字段，一个用于名字，另一个用于姓氏。现在如何访问外部 Javascript 文件中的这些字段并验证它们。
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Validation</title>
</head>
<body>
<form action="something" method="post">
FirstName:<input type="text" name="fname"/>
LastName:<input type="text" name="lname"/>
<input type="submit" value="submit">
</form>
</body>
</html>
I want to validate both First and last name using external Javascript file. how can i take the values to external Javascript file and validate. Please give me suggestions.
我想使用外部 Javascript 文件验证名字和姓氏。我如何将值带到外部 Javascript 文件并进行验证。请给我建议。
Thanks in advance.**
提前致谢。**
采纳答案by Pratap A.K
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Validation</title>
<script type="text/javascript" src="javascript.js"></script>
</head>
<body>
<form name="myform" action="something" onsubmit="return validateForm()" method="post">
FirstName:<input type="text" name="fname"/>
LastName:<input type="text" name="lname"/>
<input type="submit" value="submit">
</form>
</body>
</html>
and your java script file is(save as javascript.js)
function validateForm()
{
var x=document.forms["myform"]["fname"].value;
if(x==null || x=="" )
{
alert("name can't be left blank");
return false;
}
var y=document.forms["myform"]["lname"].value;
if(y==null || y=="")
{
alert("last name is mandatory");
return false;
}
else
{
return true;
}
}
回答by Christophe Roussy
Add an id to your fields and use getElementById
将 id 添加到您的字段并使用getElementById
For the input value HTMLInputElement
对于输入值HTMLInputElement
