# 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

Finds whether the given variable is numeric. Numeric strings consist of optional whitespace, 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) and binary (e.g. 0b10100111001) 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
$tests = array(
"42",
1337,
0x539,
02471,
0b10100111001,
1337e0,
"0x539",
"02471",
"0b10100111001",
"1337e0",
"not numeric",
array(),
9.1,
null
);
foreach ($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

### 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

- ctype_digit() - Check for numeric character(s)
- is_bool() - Finds out whether a variable is a boolean
- is_null() - Finds whether a variable is NULL
- is_float() - Finds whether the type of a variable is float
- is_int() - Find whether the type of a variable is integer
- is_string() - Find whether the type of a variable is string
- is_object() - Finds whether a variable is an object
- is_array() - Finds whether a variable is an array