PHP 5.6.7 is available

Variable handling 函数

Table of Contents

add a note add a note

User Contributed Notes 4 notes

skelley at diff dot nl
13 years ago
Sorry to say Mykolas, but your definition would not be correct.

isempty() evaluates to true for NULL, 0, "", false or 'not set' for any variable, object etc. that can be set to a value.

isset() evaluates to true if the variable, object etc. exists at all, whether it is 'empty' or not.

$foo = 0;
isset($foo); //will evaluate to true.
!empty($foo); //will evaluate to false.

isset($foo); //will evaluate to false.
!empty($foo); //will evaluate to false.
4 days ago
If you want to find out the datatype of a variable, use PHP's native gettype() function instead of various custom implementations.
jfrasca at sheerdev dot com
9 years ago
I needed a simple function that would reduce any kind of variable to a string or number while retaining some semblance of the data that was stored in the variable. This is what I came up with:

function ReduceVar ($Value) {
    switch (gettype($Value)) {
        case "boolean":
        case "integer":
        case "double":
        case "string":
        case "NULL":
            return $Value;
        case "resource":
            return get_resource_type($Value);
        case "object":
            return ReduceVar(get_object_vars($Value));
        case "array":
            if (count($Value) <= 0)
                return NULL;
                return ReduceVar(reset($Value));
            return NULL;
coding-kid at hotmail dot com
4 years ago
A simple method to check what type input var is:

class filter{
     * @var: $types (array): holds all the supported datatypes, their number, and the callback that need to be made
     *                             to check if it's valid.
    private $types = array('string'=> array('number'=> '1', 'callback'=> 'is_string'),
                            'int'=> array('number' => '2', 'callback' => 'is_int'),
                            'array'=> array('number' => '3', 'callback' => 'is_array'),
                            'object'=> array('number' => '4', 'callback' => 'is_object'),
                            'float'=> array('number' => '5', 'callback' => 'is_float'),
                            'bool'=> array('number' => '6', 'callback' => 'is_bool'),
                            'resource'=> array('number' => '7', 'callback' => 'is_resource'),
                            'null'=> array('number' => '8', 'callback' => 'is_null'));

    function __construct(){
     * @desc: This method checks what type the input variable is
     * @param: $var (mixed): The var that will be checked
     * @param: $output_type (string): How the result will be returned
     * @returns: string or int
    function type($var, $output_type = 'numeric'){

            $var_type = array("string", "1");
        } elseif(is_int($var)){
            $var_type = array("int", "2");
        } elseif(is_array($var)){
            $var_type = array("array", "3");
        } elseif(is_object($var)){
            $var_type = array("object", "4");
        } elseif(is_float($var)){
            $var_type = array("float", "5");
        } elseif(is_bool($var)){
            $var_type = array("bool", "6");
        } elseif(is_resource($var)){
            $var_type = array("resource", "7");
        } elseif(is_null($var)){
            $var_type = array("null", "8");
        if($output_type == 'text'){
            return $var_type[0];
        } else{
            return $var_type[1];
To Top