Normalizer (class)

The Normalizer class

Introduction

(PHP 5 >= 5.3.0, PHP 7, PECL intl >= 1.0.0)

Normalization is a process that involves transforming characters and sequences of characters into a formally-defined underlying representation. This process is most important when text needs to be compared for sorting and searching, but it is also used when storing text to ensure that the text is stored in a consistent representation.

The Unicode Consortium has defined a number of normalization forms reflecting the various needs of applications:

• Normalization Form D (NFD) - Canonical Decomposition
• Normalization Form C (NFC) - Canonical Decomposition followed by Canonical Composition
• Normalization Form KD (NFKD) - Compatibility Decomposition
• Normalization Form KC (NFKC) - Compatibility Decomposition followed by Canonical Composition

Class synopsis

public static bool isNormalized ( string $input [, int $form = Normalizer::FORM_C ] )

public static string normalize ( string $input [, int $form = Normalizer::FORM_C ] )

Predefined Constants

The following constants define the normalization form used by the normalizer:

Normalizer::FORM_C (integer)

Normalization Form C (NFC) - Canonical Decomposition followed by Canonical Composition

Normalizer::FORM_D (integer)

Normalization Form D (NFD) - Canonical Decomposition

Normalizer::FORM_KC (integer)

Normalization Form KC (NFKC) - Compatibility Decomposition, followed by Canonical Composition

Normalizer::FORM_KD (integer)

Normalization Form KD (NFKD) - Compatibility Decomposition

Normalizer::NONE (integer)

No decomposition/composition

Normalizer::OPTION_DEFAULT (integer)

Default normalization options

See Also

• » Unicode Normalization
• » Unicode Normalization FAQ
• » ICU User Guide - Normalization
• » ICU API Reference - Normalization

Table of Contents

• Normalizer::isNormalized — Checks if the provided string is already in the specified normalization form.
• Normalizer::normalize — Normalizes the input provided and returns the normalized string