Variable handling Functions
PHP Manual

is_numeric

(PHP 4, PHP 5, PHP 7)

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

Description

bool is_numeric ( mixed $var )

Finds whether the given variable is numeric. Numeric strings consist of optional sign, any number of digits, optional decimal part and optional exponential part. Thus +0123.45e6 is a valid numeric value. Hexadecimal (e.g. 0xf4c3b00c), Binary (e.g. 0b10100111001), Octal (e.g. 0777) notation is not allowed.

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,
    
"not numeric",
    array(),
    
9.1
);

foreach (
$tests as $element) {
    if (
is_numeric($element)) {
        echo 
"'{$element}' is numeric"PHP_EOL;
    } else {
        echo 
"'{$element}' 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' is numeric
'not numeric' is NOT numeric
'Array' is NOT numeric
'9.1' is numeric

Changelog

Version Description
7.0.0 Strings in hexadecimal (e.g. 0xf4c3b00c) notation are no longer regarded as numeric strings, i.e. is_numeric() returns FALSE now.

See Also


Variable handling Functions
PHP Manual