js生成驗證碼並驗證
阿新 • • 發佈：2019-01-02
<html> <head> <title>驗證碼</title> <style type="text/css"> #code { font-family:Arial; font-style:italic; font-weight:bold; border:0; letter-spacing:2px; color:blue; } </style> <script type = "text/javascript" src = "checkCode.js"> </script> </head> <body> <div> <input type = "text" id = "input"/> <input type = "button" id="code" onclick="createCode()"/> <input type = "button" value = "驗證" onclick = "validate()"/> </div> </body> </html>
checkCode.js
var code ; //在全域性定義驗證碼
//產生驗證碼
window.onload = function createCode(){
code = "";
var codeLength = 4;//驗證碼的長度
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');//隨機數
for(var i = 0; i < codeLength; i++) {//迴圈操作
var index = Math.floor(Math.random()*36);//取得隨機數的索引（0~35）
code += random[index];//根據索引取得隨機數加到code上
}
checkCode.value = code;//把code值賦給驗證碼
}
//校驗驗證碼
function validate(){
var inputCode = document.getElementById("input").value.toUpperCase(); //取得輸入的驗證碼並轉化為大寫
if(inputCode.length <= 0) { //若輸入的驗證碼長度為0
alert("請輸入驗證碼！"); //則彈出請輸入驗證碼
}
else if(inputCode != code ) { //若輸入的驗證碼與產生的驗證碼不一致時
alert("驗證碼輸入錯誤！@