sooip验证码demo

function _createCodeFollow(codeLength){
    var code = "";
    var selectChar = 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 charIndex = Math.floor(Math.random()*selectChar.length);
        if(charIndex % 2 == 0){
            code+=selectChar[charIndex].toLowerCase();
        }else{
            code +=selectChar[charIndex];
        }
    }
    return code;
}

console.log(_createCodeFollow(4));