(PHP 4 >= 4.0.5, PHP 5, PHP 7, PHP 8)

is_scalar Проверяет, представляет ли собой переменная скаляр


is_scalar(mixed $value): bool

Проверяет, представляет ли собой переменная скаляр.

Скалярные переменные — это переменные, содержащие int, float, string и bool. Типы array, object, resource и null — не скалярные.


Функция is_scalar() не считает ресурсы (resource) скалярными значениями, поскольку ресурсы — это абстрактные типы данных, которые пока основаны на целых числах (int). Полагаться на эту деталь не нужно, поскольку не исключено, что в будущем функция будет рассматривать ресурсы по-другому.


Функция is_scalar() не считает NULL скаляром.

Список параметров


Проверяемая переменная.

Возвращаемые значения

Возвращает true, если значение value — скаляр, иначе false.


Пример #1 Пример использования функции is_scalar()


function show_var($var)
if (
is_scalar($var)) {
} else {
$pi = 3.1416;
$proteins = array("hemoglobin", "cytochrome c oxidase", "ferredoxin");



Результат выполнения приведённого примера:

array(3) {
  string(10) "hemoglobin"
  string(20) "cytochrome c oxidase"
  string(10) "ferredoxin"

Смотрите также

  • is_float() - Проверяет, представляет ли собой переменная число с плавающей точкой
  • is_int() - Проверяет, представляет ли собой переменная целое число
  • is_numeric() - Проверяет, содержит ли переменная число или числовую строку
  • is_real() - Псевдоним is_float
  • is_string() - Проверяет, представляет ли собой тип переменной строку
  • is_bool() - Проверяет, представляет ли собой переменная логическое значение
  • is_object() - Проверяет, представляет ли собой переменная объект
  • is_array() - Определяет, представляет ли собой переменная массив

add a note

User Contributed Notes 4 notes

Dr K
18 years ago
Having hunted around the manual, I've not found a clear statement of what makes a type "scalar" (e.g. if some future version of the language introduces a new kind of type, what criterion will decide if it's "scalar"? - that goes beyond just listing what's scalar in the current version.)

In other lanuages, it means "has ordering operators" - i.e. "less than" and friends.

It (-:currently:-) appears to have the same meaning in PHP.
17 years ago
Another warning in response to the previous note:
> just a warning as it appears that an empty value is not a scalar.

That statement is wrong--or, at least, has been fixed with a later revision than the one tested. The following code generated the following output on PHP 4.3.9.

echo('is_scalar() test:'.EOL);
"NULL: " . print_R(is_scalar(NULL), true) . EOL);
"false: " . print_R(is_scalar(false), true) . EOL);
"(empty): " . print_R(is_scalar(''), true) . EOL);
"0: " . print_R(is_scalar(0), true) . EOL);
"'0': " . print_R(is_scalar('0'), true) . EOL);

is_scalar() test:
false: 1
(empty): 1
0: 1
'0': 1

* NULL is NOT a scalar
* false, (empty string), 0, and "0" ARE scalars
efelch at gmail dot com
18 years ago
A scalar is a single item or value, compared to things like arrays and objects which have multiple values. This tends to be the standard definition of the word in terms of programming. An integer, character, etc are scalars. Strings are probably considered scalars since they only hold "one" value (the value represented by the characters represented) and nothing else.
popanowel HAT hotmailZ DOT cum
19 years ago
Hi ... for newbees here, I just want to mention that reference and scalar variable aren't the same. A reference is a pointer to a scalar, just like in C or C++.

<? php // simple reference to scalar

$a = 2;
$ref = & $a;

echo "$a <br> $ref";

this should print out: "2 <br> 2".

Scalar class also exists. Look below:
<? php

class Object_t {

var $a;

function Object_t () // constructor
$this->a = 1;


$a = new Object_t; // we define a scalar object

$ref_a = &a;

echo "$a->a <br> $ref->a";

again, this should echo: "1 <br> 1";

Here is another method isued in OOP to acheive on working only over reference to scalar object. Using this, you won't ever have to ask yourself if you work on a copy of the scalar or its reference. You will only possess reference to the scalar object. If you want to duplicate the scalar object, you will have to create a function for that purpose that would read by the reference the values and assign them to another scalar of the same type... or an other type, it is as you wish at that moment.

class objet_t {

$this->a = "patate_poil";

function &
// here we create a scalar object in memory
// and we return it by reference to the calling
// control scope.
return &new $object_type;

$ref_object_t = get_ref(object_t);

"$ref_object_t->a <br>";

this should echo: "patate_poit <br>".

The only thing that I try to demonstrate is that scalar variable ARE object in memory while a reference is usualy a variable (scalar object) that contain the address of another scalar object, which contain the informations you want by using the reference.

Good Luck!

otek is popanowel HAT hotmailZ DOT cum
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