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Filters

Alpha

The Alpha filter can be used to return only alphabetic characters in the unicode "letter" category. All other characters are suppressed.

Basic Usage

$filter = new Laminas\I18n\Filter\Alpha();

echo $filter->filter('This is (my) content: 123'); // "Thisismycontent"

By default, if no locale is provided, Alpha will use the system locale provided by PHP's Locale class and the getDefault() method.

Using Whitespace

To allow whitespace characters (\s) on filtering set the option to true; otherwise they are suppressed.

$filter = new Laminas\I18n\Filter\Alpha(true);

echo $filter->filter('This is (my) content: 123'); // "This is my content"
$filter = new Laminas\I18n\Filter\Alpha();
$filter->setAllowWhiteSpace(true);

echo $filter->filter('This is (my) content: 123'); // "This is my content"

Get Current Value

To get the current value of this option, use the getAllowWhiteSpace() method.

$filter = new Laminas\I18n\Filter\Alpha(true);

$result = $filter->getAllowWhiteSpace(); // true

Default Value

The default value of this option is false that means whitespace characters are suppressed.

Using Locale

The locale string used in identifying the characters to filter (locale name, e.g. en_US).

$filter = new Laminas\I18n\Filter\Alpha(null, 'en_US');

echo $filter->filter('This is (my) content: 123'); // "Thisismycontent"
$filter = new Laminas\I18n\Filter\Alpha();
$filter->setLocale('en_US');

echo $filter->filter('This is (my) content: 123'); // "Thisismycontent"
Locale::setDefault('en_US');

$filter = new Laminas\I18n\Filter\Alpha();

echo $filter->filter('This is (my) content: 123'); // "Thisismycontent"

Get Current Value

To get the current value of this option, use the getLocale() method.

$filter = new Laminas\I18n\Filter\Alpha(null, 'en_US');

echo $filter->getLocale(); // 'en_US'

Default Value

By default, if no locale is provided, Alpha will use the system locale provided by PHP's Locale::getDefault().

Supported languages

Alpha works for most languages, except Korean, Japanese, and Chinese. Within these languages, the English alphabet is used instead of the characters from these languages. The language itself is detected using PHP's Locale class.