Check if code point is a control character

# IntlChar::iscntrl

(PHP 7, PHP 8)

IntlChar::iscntrl — Check if code point is a control character

### Description

public static IntlChar::iscntrl(int|string `$codepoint`): ?bool

Determines whether the specified code point is a control character.

A control character is one of the following:

- ISO 8-bit control character (U+0000..U+001f and U+007f..U+009f)
- `IntlChar::CHAR_CATEGORY_CONTROL_CHAR` (Cc)
- `IntlChar::CHAR_CATEGORY_FORMAT_CHAR` (Cf)
- `IntlChar::CHAR_CATEGORY_LINE_SEPARATOR` (Zl)
- `IntlChar::CHAR_CATEGORY_PARAGRAPH_SEPARATOR` (Zp)

### Parameters

`codepoint`

  The int codepoint value (e.g. `0x2603` for U+2603 SNOWMAN), or the character encoded as a UTF-8 string (e.g. `"\u{2603}"`)

### Return Values

Returns `true` if `codepoint` is a control character, `false` if not. Returns `null` on failure.

### Examples

Example #1 Testing different code points

`<?php
var_dump(IntlChar::iscntrl("A"));
var_dump(IntlChar::iscntrl(" "));
var_dump(IntlChar::iscntrl("\n"));
var_dump(IntlChar::iscntrl("\u{200e}"));
?>`

The above example will output:

    bool(false)
    bool(false)
    bool(true)
    bool(true)

### See Also

- IntlChar::isprint() - Check if code point is a printable character
- `IntlChar::PROPERTY_DEFAULT_IGNORABLE_CODE_POINT`
- ctype_cntrl() - Check for control character(s)

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