原生js实现表单的正则验证（验证通过后才可提交）

function getLength(str) {
    return str.replace(/[^\x00-xff]/g, "xx").length;
    //x00-xff表示在ascii码中所有的双字节字符，这句话意思是将所有非单字节的字符替换成xx，即两个单字节字符，然后再计算长度
}

var re_e = /^[\w_\.\-]+@[\w]+.([\w]{2,4})$/g

function findStr(str, n){
    var temp = 0;
    for(var i = 0;i<str.length;i++){
        if(str.charAt(i)==n){
            temp++:
        };
    }
}

 var　re_n =/[^\d]/g ;
 if(!re_n.test(str)){//全为数字}

 var　re_n =/[^\a-zA-Z]/g ;
 if(!re_n.test(str)){//全为字符}

function reGISter() {
    var oName = document.getElementById("name");
    var count = document.getElementById("count");
    var psw = document.getElementById("psw");
    var psw2 = document.getElementById("psw2");
    var email = document.getElementById("email");
    var name_msg = document.getElementsByClassName("name_msg")[0];
    var psw_msg = document.getElementsByClassName("psw_msg")[0];
    var psw2_msg = document.getElementsByClassName("psw2_msg")[0];
    var email_msg = document.getElementsByClassName("email_msg")[0];
    var psw = document.getElementById("psw");
    var psw2 = document.getElementById("psw2");
    var intensity = getByClass("intensity")[0].getElementsByTagName("span");
    var registerbtn = document.getElementById("submit");
    var oName_state = false;
    var email_state = false;
    var psw_state = false;
    var psw2_state = false;
    var name_length = 0;

    oName.onfocus = function() {
        name_msg.style.display = "inline-block";
    }
    oName.onkeyup = function() {
        count.style.visibility = "visible";
        name_length = getLength(this.value);
        count.innerhtml = name_length + "个字符";
        if (name_length == 0) {
            count.style.visibility = "hidden";
        }
    }
    oName.onblur = function() {
        //含有非法字符 不能为空 长度超25 长度少于6个字符
        var re = /[^\w\u4e00-\u9fa5]/g;
        if (re.test(this.value)) {
            name_msg.innerHTML = "<i class='fa fa-close'>含有非法字符</i>";
            oName_state = false;
        } else if (this.value == "") {
            name_msg.innerHTML = "<i class='fa fa-close'>不能为空</i>";
            oName_state = false;
        } else if (name_length > 25) {
            name_msg.innerHTML = "<i class='fa fa-close'>不能超出25个字符</i>";
            oName_state = false;
        } else if (name_length < 6) {
            name_msg.innerHTML = "<i class='fa fa-close'>不能少于6个字符</i>";
            oName_state = false;
        } else {
            name_msg.innerHTML = "<i class='fa fa-check-square'>OK!</i>";
            oName_state = true;
        }
        checkfORM();
    }

    psw.onfocus = function() {
        psw_msg.style.display = "inline-block";
        psw_msg.innerHTML = "<i class='fa fa-lightbulb-o'>6-16个字符，不能单独使用字母、数字或符号</i>"
    }
    psw.onkeyup = function() {
        if (this.value.length > 5) {
            intensity[1].className = "active";
            psw2.removeAttribute("disabled");
            psw2_msg.style.display = "inline-block";
        } else {
            intensity[1].className = "";
            psw2.setAttribute("disabled", "");
            psw2_msg.style.display = "none";
        }
        if (this.value.length > 10) {
            intensity[2].className = "active";
            psw2.removeAttribute("disabled");
            psw2_msg.style.display = "inline-block";
        } else {
            intensity[2].className = "";
        }
    }
    psw.onblur = function() {
        //不能为空 不能相同字符 长度6-16 不能全数字 不能全字母 
        var m = findStr(psw.value, psw.value[0]);
        var re_n = /[^\d]/g;
        var re_t = /[^a-zA-Z]/g;
        if (this.value == "") {
            psw_msg.innerHTML = "<i class='fa fa-close'>不能为空</i>";
            psw_state = false;
        } else if (m == this.value.length) {
            psw_msg.innerHTML = "<i class='fa fa-close'>不能为相同字符</i>";
            psw_state = false;
        } else if (this.value.length < 6 || this.value.legth > 16) {
            psw_msg.innerHTML = "<i class='fa fa-close'>长度应为6-16个字符</i>";
            psw_state = false;
        } else if (!re_n.test(this.value)) {
            psw_msg.innerHTML = "<i class='fa fa-close'>不能全部为数字</i>";
            psw_state = false;
        } else if (!re_t.test(this.value)) {
            psw_msg.innerHTML = "<i class='fa fa-close'>不能全部为字母</i>";
            psw_state = false;
        } else {
            psw_msg.innerHTML = "<i class='fa fa-check-square'>OK!</i>";
            psw_state = true;
        }
        checkform();
    }


    psw2.onblur = function() {
        if (psw2.value != psw.value) {
            psw2_msg.innerHTML = "<i class='fa fa-close'>两次输入不一致</i>";
            psw2_state = false;
        } else {
            psw2_msg.innerHTML = "<i class='fa fa-check-square'>OK!</i>";
            psw2_state = true;
        }
        checkform();
    }

    email.onblur = function() {
        var re_e = /^[\w_\-\.]+@[\w]+\.([\w]{2,4})$/g;
        if (!re_e.test(this.value)) {
            email_msg.innerHTML = "<i class='fa fa-close'>请输入正确的邮箱格式</i>";;
            email_state = false;
        } else {
            email_msg.innerHTML = "<i class='fa fa-check-square'>OK!</i>";
            email_state = true;
        }
        checkform();
    }
    function checkform() {
        if (oName_state && oName_state && psw_state && psw2_state) {
            registerbtn.removeAttribute("disabled");
            // registerbtn.className+=" "+"readySubmit";
            $("#submit").addClass("readySubmit");
        } else {
            registerbtn.setAttribute("disabled", "");
            //registerbtn.className = registerbtn.className.replace( new RegExp( "(\\s|^)" + "readySubmit" + "(\\s|$)" ), " " );  
            // registerbtn.className = registerbtn.className.replace( /(\s|^)readySubmit(\s|$)/g, " " );       
            $("#submit").removeClass("readySubmit");
        }
    }
}

function getLength(str) {
    return str.replace(/[^\x00-xff]/g, "xx").length;
}

function findStr(str, n) {
    var temp = 0;
    for (var i = 0; i < str.length; i++) {
        if (str.charAt(i) == n) {
            temp++;
        }
    }
    return temp;
}

<form id="form">
   <div class="name-field">
        <label>用户名</label>
        <input type="text" id="name" autofocus requiered/><span class="msg name_msg"><i class="fa fa-lightbulb-o"> 5-25个字符，1个汉字为两个字符，推荐使用中文会员名</i></span>
        <div id="count">0个字符</div>
   </div>
   <div class="email-field" requiered>
        <label>邮箱</label>
       <input type="text" id="email" /><span class="msg email_msg"></span>
       </div>
   <div class="pwd-field" requiered>
        <label>密码</label>
        <input type="passWord" id="psw" /><span class="msg psw_msg"></span>
        <div class="intensity">
            <span class="active">弱</span><span>中</span><span>强</span>
       </div>
   </div>
   <div class="pwd2-field" requiered>
        <label>确认密码</label>
        <input type="password" id="psw2" disabled="" /><span class="msg psw2_msg">请再次输入</span>
   </div>
   <button type="submit" id="submit" disabled="" class="submitBtn">注册</button>
</form>

.name-field {
    margin-top: 10px
}

.email-field {
    margin-top: 3px
}

.pwd-field {
    margin-top: 10px
}

.pwd2-field {
    margin-top: 10px
}

.register label {
    float: left;
    width: 80px;
    margin-right: 10px;
    text-align: right
}

.register .name_msg,
.register .psw_msg,
.register .psw2_msg,
.register .email_msg {
    margin-left: 10px;
    display: none
}

.intensity,
#count {
    padding-left: 90px;
    margin-top: 3px
}

#count {
    visibility: hidden;
    color: #999;
    font-size: 12px
}

.intensity span {
    display: inline-block;
    background: #FBAA51;
    width: 55px;
    height: 20px;
    text-align: center
}

.intensity .active {
    background: rgba(0, 128, 0, 0.61)
}

.register .submitBtn {
    width: 163px;
    margin: 10px 0 0 90px
}

#submit {
    color: #555
}