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 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,
    "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 is numeric
'not numeric' is NOT numeric
array () is NOT numeric
9.0999999999999996447286321199499070644378662109375 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