JavaScript 实现表单前端校验功能详解

JavaScript 表单校验实现概述

本文分享一段使用 JavaScript 实现表单校验功能的具体代码示例，供读者参考学习。

核心事件与校验逻辑

1、主要涉及以下三个事件：

onfocus（获取焦点事件）、onblur（失去焦点事件）以及 onkeyup（按键释放事件）。

2、通过事件触发相应的处理函数，在函数内部执行具体的校验逻辑。

3、利用 checkForm 函数判断表单内各项内容是否符合规范，若校验通过，则允许 submit 按钮提交表单数据。

实现效果如下：

HTML 表单部分代码如下：

<form action="demo.html" onsubmit="return checkForm()">
      <div>
      <div class="text">
           <p>用户名</p>
           <input id="value" onfocus="shoeTips('hint','用户名长度不能小于六')" onblur="hint_hide()" onkeyup="hint()" type="text" Name="Userame" placeholder="用户名" />
           <span id="hint"></span>
          </div>
         <div class="text">
           <p>密码</p>
           <input id="pass_value" onfocus="shoeTips('pass_hint','密码长度不能小于六')" onblur="pass_hide()" onkeyup="checkPass()" type="password" name="password" placeholder="密码" />
            <span id="pass_hint"></span>
            </div>
            <div class="text">
              <p>确认密码</p>
              <input id="passpass_value" onfocus="shoeTips('passpass_hint','两次密码要一致')" onblur="passpass_hide()" onkeyup="checkPassPass()" type="password" name="password" placeholder="确认密码" />
              <span id="passpass_hint"></span>
           </div>
           <div class="text">
                    <p>邮箱</p>
                    <input id="email" onfocus="shoeTips('email_hint','邮箱格式要正确')" onblur="emailHide()" onkeyup="emailCheck()" type="email" name="email" placeholder="邮箱" />
                    <span id="email_hint"></span>
                </div>
                <div class="text">
                    <p>手机号</p>
                    <input id="phone" type="text" onfocus="shoeTips('phone_hint','格式为十一位数字的手机号')" onblur="phoneHide()" onkeyup="phoneCheck()" Name="Phone" placeholder="手机号">
                    <span id="phone_hint"></span>
                </div>
                <div class="submit">
             <input type="submit" value="提交" />
         </div>
    </div>
</form>

JavaScript 脚本部分代码如下：

function shoeTips(spanId, tips) {
 var span = document.getElementById(spanId);
 span.innerHTML = tips;
}
/**
 * 校验用户名
 */
function hint() {
 var value = document.getElementById("value").value;
 var hint = document.getElementById("hint");
 if(value.length < 6) {
  hint.innerHTML = "用户名太短";
  return false;
 } else {
  hint.innerHTML = "用户名合格";
  return true;
 }
}
 
function hint_hide() {
 var hint = document.getElementById("hint");
 hint.innerHTML = "";
}
/**
 * 校验密码
 */
 
function checkPass() {
 var value = document.getElementById("pass_value").value;
 var hint = document.getElementById("pass_hint");
 if(value.length < 6) {
  hint.innerHTML = "密码太短";
  return false;
 } else {
  hint.innerHTML = "密码格式合格";
  return true;
 }
}
 
function pass_hide() {
 var hint = document.getElementById("pass_hint");
 hint.innerHTML = "";
}
/***
 * 确认密码的校验
 */
function checkPassPass() {
 var papavalue = document.getElementById("passpass_value").value;
 var value = document.getElementById("pass_value").value;
 var papahint = document.getElementById("passpass_hint");
 if(papavalue != value) {
  papahint.innerHTML = "两次密码不一致";
  return false;
 } else {
  papahint.innerHTML = "";
  return true;
 }
}
 
function passpass_hide() {
 var papahint = document.getElementById("passpass_hint");
 papahint.innerHTML = "";
}
/**
 * 校验邮箱
 */
function checkEmail(strEmail) 
{      
    var emailReg = /^([a-zA-Z0-9_-])+@([a-zA-Z0-9_-])+(\.[a-zA-Z0-9_-])+/;
    if ( emailReg.test(strEmail) ) {
        return true;
    }
    else {
//      alert("您输入的Email地址格式不正确！");
        return false;
    }
};
function emailCheck() {
 var emailValue = document.getElementById("email").value;
 var email_hint = document.getElementById("email_hint");
 var flag = checkEmail(emailValue);
 if(flag) {
  email_hint.innerHTML = "邮箱格式正确";
  return true;
 } else {
  email_hint.innerHTML = "邮箱格式错误";
  return false;
 }
}
 
function emailHide() {
 var email_hint = document.getElementById("email_hint");
 email_hint.innerHTML = "";
}
/**
 * 校验手机号
 */
function checkMobile( strMobile )
{ //13588888888
    var regu = /^[1][345678][0-9]{9}$/;
    var re = new RegExp(regu);
    if (re.test(strMobile)) {
        return true;
    }
    else {
        return false;
    }
};
function phoneCheck() {
 var phone = document.getElementById("phone").value;
 var phone_hint = document.getElementById("phone_hint");
 var flag = checkMobile(phone);
 if(flag) {
  phone_hint.innerHTML = "手机号格式正确";
  return true;
 } else {
  phone_hint.innerHTML = "手机号格式错误";
  return false;
 }
}
 
function phoneHide() {
 var phone_hint = document.getElementById("phone_hint");
 phone_hint.innerHTML = "";
}
 
function checkForm() {
 var flag = emailCheck() && checkPass() && checkPassPass() && hint() && phoneCheck();
 return flag;
}

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