preg_split

Split string by a regular expression

&reftitle.description; `array` `preg_split` `string` `pattern` `string` `subject` `int` `limit`-1 `int` `flags` 0

Split the given string by a regular expression.

&reftitle.parameters;

`pattern`

- The pattern to search for, as a string.

`subject`

- The input string.

`limit`

- If specified, then only substrings up to `limit` are returned with the rest of the string being placed in the last substring. A `limit` of -1, 0 or &null; means "no limit" and, as is standard across PHP, you can use &null; to skip to the `flags` parameter.

`flags`

- `flags` can be any combination of the following flags (combined with the `|` bitwise operator):

  `PREG_SPLIT_NO_EMPTY`

- If this flag is set, only non-empty pieces will be returned by `preg_split`.

`PREG_SPLIT_DELIM_CAPTURE`

- If this flag is set, parenthesized expression in the delimiter pattern will be captured and returned as well.

`PREG_SPLIT_OFFSET_CAPTURE`

- If this flag is set, for every occurring match the appendant string offset will also be returned. Note that this changes the return value in an array where every element is an array consisting of the matched string at offset `0` and its string offset into `subject` at offset `1`.

&reftitle.returnvalues;

Returns an array containing substrings of `subject` split along boundaries matched by `pattern`.

&reftitle.changelog;

&Version; | &Description;
4.3.0 | The `PREG_SPLIT_OFFSET_CAPTURE` was added
4.0.5 | The `PREG_SPLIT_DELIM_CAPTURE` was added

&reftitle.examples;

### `preg_split` example : Get the parts of a search string

    <?php
    // split the phrase by any number of commas or space characters,
    // which include " ", \r, \t, \n and \f
    $keywords = preg_split("/[\s,]+/", "hypertext language, programming");
    print_r($keywords);
    ?>

&example.outputs;

    Array
    (
        [0] => hypertext
        [1] => language
        [2] => programming
    )

### Splitting a string into component characters

    <?php
    $str = 'string';
    $chars = preg_split('//', $str, -1, PREG_SPLIT_NO_EMPTY);
    print_r($chars);
    ?>

&example.outputs;

    Array
    (
        [0] => s
        [1] => t
        [2] => r
        [3] => i
        [4] => n
        [5] => g
    )

### Splitting a string into matches and their offsets

    <?php
    $str = 'hypertext language programming';
    $chars = preg_split('/ /', $str, -1, PREG_SPLIT_OFFSET_CAPTURE);
    print_r($chars);
    ?>

&example.outputs;

    Array
    (
        [0] => Array
            (
                [0] => hypertext
                [1] => 0
            )

        [1] => Array
            (
                [0] => language
                [1] => 10
            )

        [2] => Array
            (
                [0] => programming
                [1] => 19
            )

    )

&reftitle.notes;

If you don't need the power of regular expressions, you can choose faster (albeit simpler) alternatives like `explode` or `str_split`.

If matching fails, an array with a single element containing the input string will be returned.

&reftitle.seealso;

- PCRE Patterns
- `implode`
- `preg_match`
- `preg_match_all`
- `preg_replace`
- `preg_last_error`