Generate image verification code and verify
A simple front-end JS to generate verification code and verify the function
<html>
<head>
<title>Verification Code</title>
<style type="text/css">
#code
{
font-style:italic;
font-weight:bold;
border:0;
letter-spacing:2px;
color: #4567ff;
background-color: #e4e4e4;
}
</style>
</head>
<body>
<div>
<form action="***" method='POST' id='loginForm'>
<input type = "text" id = "inputCode"/>
<input type = "button" id="code" onclick="createCode()"/>
<button type="button" id="submitBtn">登录</button>
</form>
</div>
</body>
</html>
$(function(){
createCode();
var code;
function createCode() {
code = "";
var codeLength = 4;
var checkCode = document.getElementById("code");
var random = new Array(0,1,2,3,4,5,6,7,8,9,'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z');
for(var i = 0; i < codeLength; i++) {
var index = Math.floor(Math.random()*36);
code += random[index];
}
checkCode.value = code;
}
$("#submitBtn").click(function () {
var inputCode = $("#inputCode").val().toUpperCase();
if(inputCode.length <= 0) {
alert("Please enter the verification code");
} else if(inputCode != code ) {
alert("Verification code input error");
createCode();
$("#inputCode").val("")
} else {
$("#loginForm").submit();
}
});
})