bcit-ci/CodeIgniter

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String Helper
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The String Helper file contains functions that assist in working with
strings.

.. important:: Please note that these functions are NOT intended, nor
    suitable to be used for any kind of security-related logic.

.. contents::
  :local:

.. raw:: html

  <div class="custom-index container"></div>

Loading this Helper
===================

This helper is loaded using the following code::

    $this->load->helper('string');

Available Functions
===================

The following functions are available:

.. php:function:: random_string([$type = 'alnum'[, $len = 8]])

    :param    string    $type: Randomization type
    :param    int    $len: Output string length
    :returns:    A random string
    :rtype:    string

    Generates a random string based on the type and length you specify.

    The first parameter specifies the type of string, the second parameter
    specifies the length. The following choices are available:

    -  **alpha**: A string with lower and uppercase letters only.
    -  **alnum**: Alpha-numeric string with lower and uppercase characters.
    -  **basic**: A random number based on ``mt_rand()``.
    -  **numeric**: Numeric string.
    -  **nozero**: Numeric string with no zeros.
    -  **md5**: An encrypted random number based on ``md5()`` (fixed length of 32).
    -  **sha1**: An encrypted random number based on ``sha1()`` (fixed length of 40).

    Usage example::

        echo random_string('alnum', 16);

    .. note:: Usage of this function is NOT suitable for password generation
        or other security-sensitive purposes. Please use
        `random_bytes() <https://secure.php.net/random_bytes>`_ instead.

.. php:function:: increment_string($str[, $separator = '_'[, $first = 1]])

    :param    string    $str: Input string
    :param    string    $separator: Separator to append a duplicate number with
    :param    int    $first: Starting number
    :returns:    An incremented string
    :rtype:    string

    Increments a string by appending a number to it or increasing the
    number. Useful for creating "copies" or a file or duplicating database
    content which has unique titles or slugs.

    Usage example::

        echo increment_string('file', '_'); // "file_1"
        echo increment_string('file', '-', 2); // "file-2"
        echo increment_string('file_4'); // "file_5"


.. php:function:: alternator($args)

    :param    mixed    $args: A variable number of arguments
    :returns:    Alternated string(s)
    :rtype:    mixed

    Allows two or more items to be alternated between, when cycling through
    a loop. Example::

        for ($i = 0; $i < 10; $i++)
        {     
            echo alternator('string one', 'string two');
        }

    You can add as many parameters as you want, and with each iteration of
    your loop the next item will be returned.

    ::

        for ($i = 0; $i < 10; $i++)
        {     
            echo alternator('one', 'two', 'three', 'four', 'five');
        }

    .. note:: To use multiple separate calls to this function simply call the
        function with no arguments to re-initialize.

.. php:function:: reduce_double_slashes($str)

    :param    string    $str: Input string
    :returns:    A string with normalized slashes
    :rtype:    string

    Converts double slashes in a string to a single slash, except those
    found in URL protocol prefixes (e.g. \http://).

    Example::

        $string = "http://example.com//index.php";
        echo reduce_double_slashes($string); // results in "http://example.com/index.php"

.. php:function:: strip_slashes($data)

    :param    mixed    $data: Input string or an array of strings
    :returns:    String(s) with stripped slashes
    :rtype:    mixed

    Removes any slashes from an array of strings.

    Example::

        $str = array(
            'question'  => 'Is your name O\'reilly?',
            'answer' => 'No, my name is O\'connor.'
        );

        $str = strip_slashes($str);

    The above will return the following array::

        array(
            'question'  => "Is your name O'reilly?",
            'answer' => "No, my name is O'connor."
        );

    .. note:: For historical reasons, this function will also accept
        and handle string inputs. This however makes it just an
        alias for ``stripslashes()``.

.. php:function:: reduce_multiples($str[, $character = ''[, $trim = FALSE]])

    :param    string    $str: Text to search in
    :param    string    $character: Character to reduce
    :param    bool    $trim: Whether to also trim the specified character
    :returns:    Reduced string
    :rtype:    string

    Reduces multiple instances of a particular character occurring directly
    after each other. Example::

        $string = "Fred, Bill,, Joe, Jimmy";
        $string = reduce_multiples($string,","); //results in "Fred, Bill, Joe, Jimmy"

    If the third parameter is set to TRUE it will remove occurrences of the
    character at the beginning and the end of the string. Example::

        $string = ",Fred, Bill,, Joe, Jimmy,";
        $string = reduce_multiples($string, ", ", TRUE); //results in "Fred, Bill, Joe, Jimmy"

.. php:function:: quotes_to_entities($str)

    :param    string    $str: Input string
    :returns:    String with quotes converted to HTML entities
    :rtype:    string

    Converts single and double quotes in a string to the corresponding HTML
    entities. Example::

        $string = "Joe's \"dinner\"";
        $string = quotes_to_entities($string); //results in "Joe&#39;s &quot;dinner&quot;"


.. php:function:: strip_quotes($str)

    :param    string    $str: Input string
    :returns:    String with quotes stripped
    :rtype:    string

    Removes single and double quotes from a string. Example::

        $string = "Joe's \"dinner\"";
        $string = strip_quotes($string); //results in "Joes dinner"