PHP is_scalar() Function

What is PHP is_scalar() Function?

If you want to know whether a variable is a scalar or not, use is_scalar() function.

What is a scalar value?

A scalar value is a single, simple value. It indicates a single piece of data. Examples of PHP scalar value are-

  • Boolean
  • Integer
  • Float
  • String

What is a non-scalar value?

A non-scalar value is a multi value which holds multiple values. Examples of PHP non-scalar value are-

  • Array
  • Object
  • Resource
  • NULL

Syntax:

is_scalar(variable)

Parameters:

The Function has 1 parameter which is required-

variable (Required): It specifies a variable.

Return Values:

The function returns-

  • TRUE, if the variable is scalar.
  • FALSE, if the variable is not scalar.

Examples:

Example 1:

<?php
echo "Is PHP a scalar value? " . (is_scalar("PHP") ? 'Yes' : 'No') . "<br />";
echo "Is 100 a scalar value? " . (is_scalar(100) ? 'Yes' : 'No') . "<br />";
echo "Is 1.5 a scalar value? " . (is_scalar(1.5) ? 'Yes' : 'No') . "<br />";
echo "Is FALSE a scalar value? " . (is_scalar(FALSE) ? 'Yes' : 'No') . "<br />";
echo "Is [1,2] a scalar value? " . (is_scalar([1, 2]) ? 'Yes' : 'No') . "<br />";
echo "Is NULL a scalar value? " . (is_scalar(NULL) ? 'Yes' : 'No');
?>

Output:

Is PHP a scalar value? Yes
Is 100 a scalar value? Yes
Is 1.5 a scalar value? Yes
Is FALSE a scalar value? Yes
Is [1,2] a scalar value? No
Is NULL a scalar value? No

Practical usage of PHP is_scalar() function:

  • In your program when a function only accept simple value and no complex data types, use is_scalar() function.
  • When a filed in your database table only accepts single value, you can use is_scalar() function to ensure it.
  • You can use is_scalar() function to detect a non scalar variable so that you can display it properly in the display using functions like print_r() or var_dump() function.
  • You can use is_scalar() function before using some function that only operates on single values.

Note:

NULL is not considered a scalar value.

PHP Version Support:

PHP 4, PHP 5, PHP 7, PHP 8

Summary: PHP is_scalar() Function

is_scalar() is a built-in variable handling function. It is a simple but very effective function to determine whether a value is scalar or not.

Reference:

https://www.php.net/manual/en/function.is-scalar.php