PHP表单验证之必填字段--w3school学习笔记 w3school离线手册 w3school tiy w3school手册下载

<code><span><span>html</span>></span><span>head</span>><span>title</span>><span><span>title</span>></span><span><span>head</span>></span><span>body</span>><span>form</span><span>action</span>=<span>htmlspecialchars("<?php </span><span>echo</span> $<span>_SERVER</span>['<span>PHP_SELF</span>']; ?></span>") method='post'>
        姓名:<span>input</span><span>type</span>=<span>'text'</span><span>name</span>=<span>'name'</span> /><span>span</span><span>style</span>=<span>'color:red'</span>>*<span><span><?php </span><span>echo</span><span>$name_Err</span>; <span>?></span></span><span><span>span</span>></span><span>br</span>/></span>
        电邮:<span>input</span><span>type</span>=<span>'text'</span><span>name</span>=<span>'email'</span> /><span>span</span><span>style</span>=<span>'color:red'</span>>*<span><span><?php </span><span>echo</span><span>$email_Err</span>; <span>?></span></span><span><span>span</span>></span><span>br</span>/></span>
        网址:<span>input</span><span>type</span>=<span>'text'</span><span>name</span>=<span>'website'</span> /><span>br</span>/>
        评论:<span>textarea</span><span>name</span>=<span>'comment'</span><span>rows</span>=<span>3</span><span>cols</span>=<span>21</span>><span><span>textarea</span>></span><span>br</span>/>
        性别:<span>input</span><span>type</span>=<span>"radio"</span><span>name</span>=<span>'gender'</span><span>value</span>=<span>0</span><span>checked</span>=<span>'checked'</span>/>女性
        <span>input</span><span>type</span>=<span>"radio"</span><span>name</span>=<span>'gender'</span><span>value</span>=<span>1</span> />男性<span>br</span>/><span>input</span><span>type</span>=<span>'submit'</span><span>value</span>=<span>'提交'</span> /><span><span>form</span>></span><span><span>body</span>></span><span><span>html</span>></span></code>

<code><span><span><?php </span><span>$name</span>=<span>$email</span>=<span>$website</span>=<span>$comment</span>=<span>''</span>;
<span>$name_Err</span>=<span>$email_Err</span>=<span>''</span>;<span>//存储错误信息</span><span>if</span>(<span>$_SERVER</span>[<span>'REQUEST_METHOD'</span>]==<span>'POST'</span>){
    <span>if</span>(<span>$_POST</span>[<span>'name'</span>]==<span>''</span>){
        <span>$name_Err</span>=<span>'姓名不能为空'</span>;
    }<span>else</span>{
        <span>$name</span>=test_input(<span>$_POST</span>[<span>'name'</span>]);
    }
    <span>if</span>(<span>$_POST</span>[<span>'email'</span>]==<span>''</span>){
        <span>$email_Err</span>=<span>'邮箱不能为空'</span>;
    }<span>else</span>{
        <span>$email</span>=test_input(<span>$_POST</span>[<span>'email'</span>]);
    }
    <span>$website</span>=test_input(<span>$_POST</span>[<span>'website'</span>]);
    <span>$comment</span>=test_input(<span>$_POST</span>[<span>'comment'</span>]);
    <span>//由于我在html中将女性默认为选中，因此性别不用验证是否为空</span><span>$gender</span>=test_input(<span>$_POST</span>[<span>'gender'</span>]);
}

<span><span>function</span><span>test_input</span><span>(<span>$data</span>)</span>{</span><span>$data</span>=trim(<span>$data</span>);
    <span>$data</span>=stripslashes(<span>$data</span>);
    <span>$data</span>=htmlspecialchars(<span>$data</span>);
    <span>return</span><span>$data</span>;
}







<span>?></span></span></span></code>