is_numeric

(PHP 4, PHP 5)

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 allowed too but only without sign, decimal and exponential part.

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

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