grapheme_strlen - PHP code example

The php Function Grapheme_Strlen Gets the Length of a String in PHP

PHP supports a wide variety of functions that aid in the manipulation of strings, or sequences of characters. The php function grapheme_strlen is one of these string functions that you might use in your program to get the length of a particular string. Functions are an important part of a programming language, because they help to promote code readability by separating logical operations into small, self-contained units that are easier to understand and maintain.

Getting the length of a string in PHP is often necessary to validate form input or to make sure that a field in your database has enough space for the value that you are passing into it. While you can always use the php function strlen() to determine this, this function is not the best choice when working with multibyte encoded strings since it counts bytes instead of characters.

If you are working with a multibyte string that contains characters from the unicode family, you should use the mb_strlen() function instead of the php function strlen() to measure the length of your string. This is because the strlen() function doesn’t take into account null bytes, whereas mb_strlen() does.

Another common function that is used to measure the length of a string is the php function strpos(). This function takes three arguments: the string to look for, a position within the string where you want to start searching for needle and a second argument which indicates how far you have searched for needle from the beginning of the string.

grapheme_strlen example

if (!function_exists('grapheme_extract')) {
    function grapheme_extract(?string $haystack, ?int $size, ?int $type = GRAPHEME_EXTR_COUNT, ?int $offset = 0, &$next = null): string|false { return p\Grapheme::grapheme_extract((string) $haystack, (int) $size, (int) $type, (int) $offset, $next); }
}
if (!function_exists('grapheme_stripos')) {
    function grapheme_stripos(?string $haystack, ?string $needle, ?int $offset = 0): int|false { return p\Grapheme::grapheme_stripos((string) $haystack, (string) $needle, (int) $offset); }
}
if (!function_exists('grapheme_stristr')) {
    function grapheme_stristr(?string $haystack, ?string $needle, ?bool $beforeNeedle = false): string|false { return p\Grapheme::grapheme_stristr((string) $haystack, (string) $needle, (bool) $beforeNeedle); }
}
if (!function_exists('grapheme_strlen')) {
    function grapheme_strlen(?string $string): int|false|null { return p\Grapheme::grapheme_strlen((string) $string); }
}
if (!function_exists('grapheme_strpos')) {
    function grapheme_strpos(?string $haystack, ?string $needle, ?int $offset = 0): int|false { return p\Grapheme::grapheme_strpos((string) $haystack, (string) $needle, (int) $offset); }
}
if (!function_exists('grapheme_strripos')) {
    function grapheme_strripos(?string $haystack, ?string $needle, ?int $offset = 0): int|false { return p\Grapheme::grapheme_strripos((string) $haystack, (string) $needle, (int) $offset); }
}
if (!function_exists('grapheme_strrpos')) {
    function grapheme_strrpos(?string $haystack, ?string $needle, ?int $offset = 0): int|false { return p\Grapheme::grapheme_strrpos((string) $haystack, (string) $needle, (int) $offset); }
}
if (!function_exists('grapheme_strstr')) {

0xC3, 0xA4], 'Späßchen', 2],
                [[0xC3, 0x9F], 'Späßchen', -5],
            ]
        );
    }

    /** * @dataProvider provideCodePointsAt */
    public function testCodePointsAt(array $expected, string $string, int $offset, int $form = null)
    {
        if (2 !== grapheme_strlen('च्छे') && 'नमस्ते' === $string) {
            $this->markTestSkipped('Skipping due to issue ICU-21661.');
        }

        $instance = static::createFromString($string);
        $instance = $form ? $instance->normalize($form) : $instance;

        $this->assertSame($expected, $instance->codePointsAt($offset));
    }

    public static function provideCodePointsAt(): array
    {

catch (\ValueError $e) {
            if (!str_starts_with($e->getMessage(), 'mb_check_encoding(): Argument #2 ($encoding) must be a valid encoding')) {
                throw $e;
            }

            $invalidCharset = true;
        }

        $length = $invalidCharset ? 0 : match ($constraint->countUnit) {
            Length::COUNT_BYTES => \strlen($stringValue),
            Length::COUNT_CODEPOINTS => mb_strlen($stringValue, $constraint->charset),
            Length::COUNT_GRAPHEMES => grapheme_strlen($stringValue),
        };

        if ($invalidCharset || false === ($length ?? false)) {
            $this->context->buildViolation($constraint->charsetMessage)
                ->setParameter('{{ value }}', $this->formatValue($stringValue))
                ->setParameter('{{ charset }}', $constraint->charset)
                ->setInvalidValue($value)
                ->setCode(Length::INVALID_CHARACTERS_ERROR)
                ->addViolation();

            return;
        }

$form = null === $this->ignoreCase ? \Normalizer::NFD : \Normalizer::NFC;
        normalizer_is_normalized($needle, $form) ?: $needle = normalizer_normalize($needle, $form);

        if ('' === $needle || false === $needle) {
            return null;
        }

        $string = $this->string;

        if (0 > $offset) {
            // workaround https://bugs.php.net/74264             if (0 > $offset += grapheme_strlen($needle)) {
                $string = grapheme_substr($string, 0, $offset);
            }
            $offset = 0;
        }

        $i = $this->ignoreCase ? grapheme_strripos($string, $needle, $offset) : grapheme_strrpos($string, $needle, $offset);

        return false === $i ? null : $i;
    }

    public function join(array $strings, string $lastGlue = null): static
    {

if (!function_exists('grapheme_extract')) {
    function grapheme_extract($haystack, $size, $type = 0, $start = 0, &$next = 0) { return p\Grapheme::grapheme_extract($haystack, $size, $type, $start, $next); }
}
if (!function_exists('grapheme_stripos')) {
    function grapheme_stripos($haystack, $needle, $offset = 0) { return p\Grapheme::grapheme_stripos($haystack, $needle, $offset); }
}
if (!function_exists('grapheme_stristr')) {
    function grapheme_stristr($haystack, $needle, $beforeNeedle = false) { return p\Grapheme::grapheme_stristr($haystack, $needle, $beforeNeedle); }
}
if (!function_exists('grapheme_strlen')) {
    function grapheme_strlen($input) { return p\Grapheme::grapheme_strlen($input); }
}
if (!function_exists('grapheme_strpos')) {
    function grapheme_strpos($haystack, $needle, $offset = 0) { return p\Grapheme::grapheme_strpos($haystack, $needle, $offset); }
}
if (!function_exists('grapheme_strripos')) {
    function grapheme_strripos($haystack, $needle, $offset = 0) { return p\Grapheme::grapheme_strripos($haystack, $needle, $offset); }
}
if (!function_exists('grapheme_strrpos')) {
    function grapheme_strrpos($haystack, $needle, $offset = 0) { return p\Grapheme::grapheme_strrpos($haystack, $needle, $offset); }
}
if (!function_exists('grapheme_strstr')) {

$this->assertSame('', (string) $instance);
        $this->assertSame(0, $instance->length());
        $this->assertTrue($instance->isEmpty());
    }

    /** * @dataProvider provideBytesAt */
    public function testBytesAt(array $expected, string $string, int $offset, int $form = null)
    {
        if (2 !== grapheme_strlen('च्छे') && 'नमस्ते' === $string) {
            $this->markTestSkipped('Skipping due to issue ICU-21661.');
        }

        $instance = static::createFromString($string);
        $instance = $form ? $instance->normalize($form) : $instance;

        $this->assertSame($expected, $instance->bytesAt($offset));
    }

    public static function provideBytesAt(): array
    {

if (80000 > \PHP_VERSION_ID && !preg_match('/./us', $needle)) {
            return false;
        }
        $s = (string) $s;
        if (!preg_match('/./us', $s)) {
            return false;
        }
        if ($offset > 0) {
            $s = self::grapheme_substr($s, $offset);
        } elseif ($offset < 0) {
            if (2 > $mode) {
                $offset += self::grapheme_strlen($s);
                $s = self::grapheme_substr($s, $offset);
                if (0 > $offset) {
                    $offset = 0;
                }
            } elseif (0 > $offset += self::grapheme_strlen($needle)) {
                $s = self::grapheme_substr($s, 0, $offset);
                $offset = 0;
            } else {
                $offset = 0;
            }
        }