Variable handling Functions
PHP Manual

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 notation (0xFF) 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
        
"1e4"
        
"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
'1e4' is numeric
'not numeric' is NOT numeric
'Array' is NOT numeric
'9.1' is numeric

See Also


Variable handling Functions
PHP Manual