表单验证
- 拿到表单内容进行非空验证（单独函数封装，方便后面调用）
- 为空则向P里面加内容
- 要阻断表单提交，不然直接跳走了
e.preventDefault() - 提交时要判定是否为空
- 键值提交也要判定是否为空
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<style>
div {
width: 600px;
height: 600px;
margin: 50px auto;
background-color: skyblue;
padding: 20px;
}
div input {
width: 520px;
height: 50px;
margin-top: 50px;
}
</style>
</head>
<body>
<div>
<form action="">
<input type="text" name="name" placeholder="输入用户名"><br>
<p class="nameTip"></p>
<input type="password" name="password" placeholder="输入密码"><br>
<p class="passwordTip"></p>
<input type="submit" name="submit" value="按钮">
</form>
</div>
<script>
var formEle = document.querySelector('form')
var nameinput = document.querySelector('input[name="name"]')
var passwordinput = document.querySelector('input[name="password"]')
var pnameTip = document.querySelector('.nameTip')
var ppasswordTip = document.querySelector('.passwordTip')
//是否为空判定
function checkUserNameNull(){
if(nameinput.value==''){
pnameTip.innerHTML='输入名字'
return false
}else{
pnameTip.innerHTML=''
return true
}
}
//失去焦点进行用户名是否为空验证
nameinput.οnblur=function (){
checkUserNameNull()
}
//是否为空判定
function checkPasswordNull(){
if(passwordinput.value==''){
ppasswordTip.innerHTML='输入名字'
return false
}else{
ppasswordTip.innerHTML=''
return true
}
}
//失去焦点进行密码框是否为空验证
passwordinput.οnblur=function (){
checkPasswordNull()
}
//提交时验证
formEle.onsubmit = function (e) {
e.preventDefault()
//阻止表单默认提交
var nameisok=checkUserNameNull()
var passwordisok= checkPasswordNull()
//都满足不为空提交
if(nameisok && passwordisok){
location.href = 'https://www.baidu.com/'
}
}
//键值提交
document.οnkeyup=function (e){
var keyCode=e.keyCode|| e.which
if(keyCode==13&&e.shiftKey){
var nameisok=checkUserNameNull()
var passwordisok= checkPasswordNull()
if(nameisok && passwordisok){
location.href = 'https://www.baidu.com/'
}
}
}
</script>
</body>
</html>
