bootstrap4简单使用和入门01-简单表单的使用

基本表单页面

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>basic01</title>
    <style type="text/css">
        #result {
            display: none;
        }
        .title{
            margin-top: 50px;
            margin-bottom: 50px;
        }

    </style>
</head>
<body>
    <h2 class="title">注册</h2>
    <form id="myForm">
        <div>
            <label>姓名</label>
            <input type="text" name="name">
        </div>

        <div>
            <label>密码</label>
            <input type="password" name="password">
        </div>

        <div>
            <label>电话</label>
            <input type="text" name="cellphone">
        </div>

        <div>
            <label>地址</label>
            <input type="text" name="address">
        </div>

        <div id="result">

        </div>
        <div>
            <button type="submit" name="register">提交</button>
        </div>
    </form>
    <script type="text/javascript">
        var form = document.querySelector("#myForm")
        var result = document.querySelector("#result")
        form.addEventListener('submit', function(e){
            if(!document.querySelector('[name=password]').value){
                result.style.display = 'block';
                result.innerHTML = '密码为空';
            }else{
                result.style.display = 'none';
            }
            e.preventDefault();
        });
    </script>
</body>
</html>

引入bootstrap

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>basic01</title>
    <style type="text/css">
        #result {
            display: none;
        }
        .title{
            margin-top: 50 px;
            margin-bottom: 50 px;
        }
        .operate button{
            margin: 0 auto;
        }

    </style>
    <link rel="stylesheet" type="text/css" href="bootstrap-4.0.0-dist/css/bootstrap.min.css">
</head>
<body>
    <h2 class="title col-6 offset-3">注册</h2>
    <form id="myForm" class="col-6 offset-3">
        <div class="form-group row">
            <label class="col-2 col-form-label">姓名</label>
            <div class="col-10">
                <input class="form-control" type="text" name="name">
            </div>
        </div>

        <div class="form-group row">
            <label class="col-2 col-form-label">密码</label>
            <div class="col-10">
                <input class="form-control" type="password" name="password">
            </div>
        </div>

        <div class="form-group row">
            <label class="col-2 col-form-label">电话</label>
            <div class="col-10">
                <input class="form-control" type="text" name="cellphone">
            </div>
        </div>

        <div class="form-group row">
            <label class="col-2 col-form-label">地址</label>
            <div class="col-10">
                <input class="form-control" type="text" name="address">
            </div>
        </div>

        <div id="result" class="form-group row alert alert-danger">

        </div>
        <div class="operate form-group row">
            <button class="btn btn-primary" type="submit" name="register">提交</button>
        </div>
    </form>
    <script type="text/javascript">
        var form = document.querySelector("#myForm")
        var result = document.querySelector("#result")
        form.addEventListener('submit', function(e){
            if(!document.querySelector('[name=password]').value){
                result.style.display = 'block';
                result.innerHTML = '密码为空';
            }else{
                result.style.display = 'none';
            }
            e.preventDefault();
        });
    </script>
</body>
</html>