is_numeric

Finds whether a variable is a number or a numeric string

&reftitle.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.

&reftitle.parameters;

`var`

- The variable being evaluated.

&reftitle.returnvalues;

Returns &true; if `var` is a number or a numeric string, &false; otherwise.

&reftitle.examples;

### `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;
        }
    }
    ?>

&example.outputs;

    '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

&reftitle.seealso;

- `ctype_digit`
- `is_bool`
- `is_null`
- `is_float`
- `is_int`
- `is_string`
- `is_object`
- `is_array`