以下情况,会视为false: the boolean FALSE itself the integer 0 (zero) the float 0.0 (zero) the empty string, and the string "0" an array with zero elements an object with zero member variables (PHP 4 only) the special type NULL (including unset variables) SimpleXML objects created from empty tags if(FALSE) { 为TRUE时执行 }
if($istable)这个判断就为真。
以下情况,会视为false:
the boolean FALSE itself
the integer 0 (zero)
the float 0.0 (zero)
the empty string, and the string "0"
an array with zero elements
an object with zero member variables (PHP 4 only)
the special type NULL (including unset variables)
SimpleXML objects created from empty tags if(FALSE)
{
为TRUE时执行
}
//运行
} if(false) {
//不运行
}