String Helper

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.

Loading this Helper

This helper is loaded using the following code:

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

Available Functions

The following functions are available:

random_string([$type = 'alnum'[, $len = 8]])
Parameters:
  • $type (string) – Randomization type
  • $len (int) – Output string length
Returns:

A random string
Return type:

string

Generates a random string based on the type and length you specify. Useful for creating passwords or generating random hashes.

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 the unique and encrypt types is DEPRECATED. They are just aliases for md5 and sha1 respectively.

increment_string($str[, $separator = '_'[, $first = 1]])
Parameters:
  • $str (string) – Input string
  • $separator (string) – Separator to append a duplicate number with
  • $first (int) – Starting number
Returns:

An incremented string
Return type:

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"
alternator($args)
Parameters:
  • $args (mixed) – A variable number of arguments
Returns:

Alternated string(s)
Return type:

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.

repeater($data[, $num = 1])
Parameters:
  • $data (string) – Input
  • $num (int) – Number of times to repeat
Returns:

Repeated string
Return type:

string

Generates repeating copies of the data you submit. Example:

$string = "\n";
echo repeater($string, 30);

The above would generate 30 newlines.

Note

This function is DEPRECATED. Use the native str_repeat() instead.

reduce_double_slashes($str)
Parameters:
  • $str (string) – Input string
Returns:

A string with normalized slashes
Return type:

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"
strip_slashes($data)
Parameters:
  • $data (mixed) – Input string or an array of strings
Returns:

String(s) with stripped slashes
Return type:

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().

trim_slashes($str)
Parameters:
  • $str (string) – Input string
Returns:

Slash-trimmed string
Return type:

string

Removes any leading/trailing slashes from a string. Example:

$string = "/this/that/theother/";
echo trim_slashes($string); // results in this/that/theother

Note

This function is DEPRECATED. Use the native trim() instead: | | trim($str, ‘/’);

reduce_multiples($str[, $character = ''[, $trim = FALSE]])
Parameters:
  • $str (string) – Text to search in
  • $character (string) – Character to reduce
  • $trim (bool) – Whether to also trim the specified character
Returns:

Reduced string
Return type:

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"
quotes_to_entities($str)
Parameters:
  • $str (string) – Input string
Returns:

String with quotes converted to HTML entities
Return type:

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;"
strip_quotes($str)
Parameters:
  • $str (string) – Input string
Returns:

String with quotes stripped
Return type:

string

Removes single and double quotes from a string. Example:

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