cookie简单实例：

<?php

      if($_GET['out']){    //注销cookie      setcookie('id','');         setcookie('password','');         echo "<script>location.href='cookie.php'</script>";      //因为cookies不是及时生效的，只有你再次刷新时才生效，所以，注销后让页面自动刷新。   }   //如果用户名和密码是否同时存在，设置cookie  if($_POST['name'] && $_POST['password']){       setcookie('id',$_POST['name'],time()+3600);      setcookie('password',$_POST['password'],time()+3600);      echo "<script>location.href='cookie.php'</script>";   }   //判断cookies设置成功后，显示cookie   if($_COOKIE['id']&&$_COOKIE['password']){       echo "登录成功<br>";      echo "用户名：".$_COOKIE['id']."<br>";      echo "密码：".$_COOKIE['password']."<br>";      echo "<a href='cookie.php?out=out'>注销cookie</a>";         }?><form action="cookie.php" method="POST">用户名：<input type="text" name="name"><br>密  码: <input type="password" name="password"><br><input type="submit" name="submit" value="提交"></form>

session简单实例：

<?php

    //开启session,必须放在第一句，否则会出错。    session_start();    if($_GET['out']){        unset($_SESSION['id']);       unset($_SESSION['password']);    }    if($_POST['name']&&$_POST['password']){          $_SESSION['id']=$_POST['name'];         $_SESSION['password']=$_POST['password'];    }    if($_SESSION['id']&&$_SESSION['password']){         echo "登录成功<br>";        echo "用户名：".$_SESSION['id']."<br>";        echo "密码：".$_SESSION['password']."<br>";        echo "<a href='session.php?out=out'>注销session</a>";    }?><form action="session.php" method="POST">用户名：<input type="text" name="name"><br>密  码: <input type="password" name="password"><br><input type="submit" name="submit" value="提交"></form>