<?php
$username = "dee"   //少了分号;
echo $username;

( ! ) Parse error: syntax error, unexpected T_ECHO in D:\practise\php\Error\error1.php on line 3

<?php
if(ereg('dee', 'welcome to dee\'s medows', $matches)){
    print_r($matches);
}else{
    echo 'not found';
}

( ! ) Deprecated: Function ereg() is deprecated in D:\practise\php\Error\error1.php on line 2
Array ( [0] => dee )

<?php
echo mysql_escape_string('\' or 1 = 1 #');

Deprecated：mysql_escape_string()：This Function id deprecated: use mysql_real_escape_string() instead. in ****
\' or 1 = 1 #

<?php
echo $dee;
//程序继续执行
echo 'continue';

( ! ) Notice: Undefined variable: dee in D:\practise\php\Error\error1.php on line 2
continue

<?php
$userInfo = array('username'=>'dee', 'age'=>28);
echo $userInfo['username'];
echo '<hr>';
echo $userInfo[age]; //会产生 notice 级别的错误
echo '<hr>';

echo 'continue';

dee
( ! ) Notice: Use of undefined constant age - assumed 'age' in D:\practise\php\Error\error1.php on line 5
28
continue

<?php
settype($var, 'int'); // 变量 var 的类型设置为 int
var_dump($var);

//设置一个不存在的类型,warning
settype($var, 'dee');
var_dump($var);

echo 'continue';

int 0
( ! ) Warning: settype() [function.settype]: Invalid type in D:\practise\php\Error\error1.php on line 6
 int 0
continue