bool和 == 运算的问题
在php官方的手册当中提供了这样一个例子：
<br />Beware of certain control behavior with boolean and non boolean values :<br /><br /><?php<br />// Consider that the 0 could by any parameters including itself<br />var_dump(0 == 1); // false<br />var_dump(0 == (bool)'all'); // false<br />var_dump(0 == 'all'); // TRUE, take care<br />var_dump(0 === 'all'); // false<br /><br />// To avoid this behavior, you need to cast your parameter as string like that :<br />var_dump((string)0 == 'all'); // false<br />?> <br />
