PHP preg_split()

Introduction to PHP preg_split()

The following article provides an outline on PHP preg_split(). preg_split() is a predefined inbuilt function which helps in converting the prescribed string into an array. This predefined function will split the given string into smaller/sub strings which is having some length as specified by the system user. This function also come in handy like limiting the small string or the sub strings up to some limit which returns through an array. It is analogous to explode() but the only difference is regular expression used for delimiter instead or explode().

Syntax with Parameters

Following is a syntax with parameters and explanation:

Syntax:

array preg_split( $pattern, $subject, $limit, $flag )

Parameters:

The preg_split() function usually accepts four parameters just as mentioned in the above syntax.

1. Pattern: The type of value used in the preg_split() function is string type in which the pattern will search as a string if not it will separate the elements.

2. Subject: The $subject parameter is the variable which usually helps in storing the input string.

3. Limit: The limit parameter will indicate the limit of the preg_split() function. If the limit of the function is defined then small string or the sub string will be returned only up to the limit. If the limit is either “0” or “-1”, the limit parameter will be assigned as “no limit” then it is used by the “$strflag” (flag).

4. Flag: The flag/flags parameter helps to signalize and flag’s variable type/types is used to indicate the two state TRUE or two state FALSE in order to control the program.

It has different combinations of flags:

• PREG_SPLIT_NO_EMPTY: If the flag parameter/variable is set to the “PREG_SPLIT_NO_EMPTY”, preg_split() function will return only non-empty pieces.
• PREG_SPLIT_DELIM_CAPTURE: If the flag parameter is set to the “PREG_SPLIT_DELIM_CAPTURE”, delimiter pattern of the parenthesized expression will be returned and captured.
• PREG_SPLIT_OFFSET_CAPTURE: If the flag parameter is set to the “PREG_SPLIT_OFFSET_CAPTURE”, for each and every occurring match string offset is going to be returned and also helps in changing the return value of the array in which the matched string offset will be set to the “0” value and the input string offset value is set to the value “1”.

How preg_split() Function works in PHP?

• The preg_split() function will help in returning the array when the split boundaries are matched.
• The preg_split() function will return an array element only when the original array or the string’s limit exceeds because the condition is TRUE otherwise it will be FALSE.
• Preg_split() function works by splitting some terms/text/special characters from the original string text provided and then stores in a specific mentioned variables name’s index values which is nothing but in an array.
• One can call all those values which are split using the index values of the array like array[0] etc..

Examples of PHP preg_split()

Given below are the examples:

Example #1

This is the example of illustrating the preg_split() function of PHP programming language. In the below syntax, a variable “$inputstrVal1” is created and assigned a string “PavanSake” to it. Then a variable “$result1” is created by assigning the preg_split() function to it with the basic four parameters as mentioned in the syntax. Here “//” is the pattern parameter, input string value given is the subject parameter which is to be splitted, “-1” is the limit value which means it has no limit and splitting will be done up to the end of the string and the normal FLAG parameter used as usually based on our requirement. Then the “$result1” variable value will be printed with the help of “print_r()” function.

Syntax:

<?php
$inputstrVal1  = 'PavanSake';
$result1 = preg_split('//', $inputstrVal1 , -1, PREG_SPLIT_NO_EMPTY);
print_r($result1);
?>

Output:

Example #2

This is also one of the example of preg_split() function of PHP Programming Language. Here the phrase will be split by the number of commas. Usually the space characters are “\r”, “\t”, “\n”, “\f”. In the below example, a variable “$result11” is created by assigning the preg_split() function. It contains only 2 parameters by giving the string input “Pavan Kumar Sake” directly. Then the result of the “$result11” will be printed with the help of the “print_r()” function.

Syntax:

<?php
$result11 = preg_split("/[\s,]+/", "Pavan Kumar Sake");
print_r($result11);
?>

Output:

Example #3

This is the example of preg_split() function illustration of the PHP language. In the below example, at first a variable is created by assigning a string value which is actually a hyper link to provide the string input. Then again a pattern string value is given with some text and special characters. Then a result variable is created by assigning preg_split() function with 4 specific parameter variables. Then a print_r() function is used to show the array elements from the string. In the output, you will get the text in the array elements and it’s index by filtering the mentioned pattern string elements from the input string value.

Syntax:

<?php
$inputstrVal1 = "http://profitloops.in/pavan/kumar/sake.php";
$patternstrVal1= "/[http:\/\/|\.]/";
$result12 = preg_split($patternstrVal1, $inputstrVal1, 0,
PREG_SPLIT_NO_EMPTY | PREG_SPLIT_OFFSET_CAPTURE);
print_r($result12 );
?>

Output:

Example #4

This is the example of showing how to split the id address using the preg_split() function. At first, echo statement is used inside the PHP tags just to print some text when the program executed. Then a variable “$ip1” is created by assigning the string value which contains the IP address. Then one more variable is created to assign the preg_split() function. This will make the string to become array elements after splitting. Then by using the print statement we are going to print the array elements using the index values.

Syntax:

<?php
echo "Application :: This is the program of splitting the ip address";
$ip1 = "111.422.732.001";
$iparr1 = preg_split ("/\./", $ip1);
print "$iparr1[0] <br />";
print "$iparr1[1] <br />" ;
print "$iparr1[2] <br />"  ;
print "$iparr1[3] <br />"  ;
?>

Output:

Conclusion

Here we saw introduction on PHP preg_split() function and it’s syntax with parameters, how the preg_split() function works in PHP along with the various examples to implement preg_split() function.

This is a guide to PHP preg_split(). Here we discuss the introduction, how preg_split() function works in PHP with respective examples. You may also have a look at the following articles to learn more –

1. PHP Serialize
2. PHP Tag in HTML
3. PHP Date Time Functions
4. PHP Pagination