Finds whether a variable is a number or a numeric string

is_null
is_object
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

- 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

is_null
is_object
Variable handling Functions
PHP Manual