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is_numeric

(PHP 4, PHP 5, PHP 7)

is_numeric — Finds whether a variable is a number or a numeric string

Description

is_numeric ( mixed $var ) : bool

Determines if the given variable is a number or a numeric string.

Parameters

var

The variable being evaluated.

Return Values

Returns true if var is a number or a numeric string, false otherwise.

Examples

Example #1 is_numeric() examples

<?php
$tests = array(
    "42",
    1337,
    0x539,
    02471,
    0b10100111001,
    1337e0,
    "0x539",
    "02471",
    "0b10100111001",
    "1337e0",
    "not numeric",
    array(),
    9.1,
    null
);

foreach ($tests as $element) {
    if (is_numeric($element)) {
        echo var_export($element, true) . " is numeric", PHP_EOL;
    } else {
        echo var_export($element, true) . " is NOT numeric", PHP_EOL;
    }
}
?>

The above example will output:

'42' is numeric
1337 is numeric
1337 is numeric
1337 is numeric
1337 is numeric
1337.0 is numeric
'0x539' is NOT numeric
'02471' is numeric
'0b10100111001' is NOT numeric
'1337e0' is numeric
'not numeric' is NOT numeric
array (
) is NOT numeric
9.1 is numeric
NULL is NOT numeric

See Also

© 1997–2020 The PHP Documentation Group
Licensed under the Creative Commons Attribution License v3.0 or later.
https://www.php.net/manual/en/function.is-numeric.php