explode()

The explode() function splits a string into an array of substrings, breaking it apart wherever a chosen delimiter appears. It is the standard PHP way to turn delimited text — a CSV row, a date, a comma-separated tag list — into data you can loop over. It is the inverse of implode(), which joins an array back into a string.

This page covers the syntax, the optional $limit parameter (including negative values), the return value, common parsing patterns, and the gotchas that trip people up.

Syntax

explode(string $separator, string $string, int $limit = PHP_INT_MAX): array

The function returns an array of strings. If $separator is an empty string (""), explode() throws a ValueError (in PHP 8+; in older versions it returned false). If the separator never appears in the string, the result is a one-element array containing the whole original string.

Basic example

We define the delimiter ,, call explode(), and print_r() the resulting array. Each element is everything between two delimiters.

The output of this code will be:

Array
(
    [0] => Hello
    [1] => World!
)

Limiting the number of pieces

The optional $limit parameter changes how the string is broken up:

• Positive limit — the array contains at most that many elements; the last element holds the unsplit remainder of the string.
• Zero — treated as 1, so the whole string is returned as a single element.
• Negative limit — all pieces are returned except the last |limit| of them.

Positive limit

With a limit of 3, the string is split into at most three elements. Note that the final element keeps the rest of the string unsplit — three,four,five — rather than being discarded.

The output of this code will be:

Array
(
    [0] => one
    [1] => two
    [2] => three,four,five
)

This is handy when you only care about the first few fields, for example explode(' ', $logLine, 2) to separate a timestamp from the rest of a log message.

Negative limit

A negative limit drops elements from the end of the result:

<?php
$string = "one,two,three,four,five";
print_r(explode(",", $string, -2));
?>

The last two pieces (four and five) are removed:

Array
(
    [0] => one
    [1] => two
    [2] => three
)

Common parsing patterns

A typical real-world use is reading a delimited record and trimming each field:

<?php
$csvRow = "Jane , Doe ,  [email protected] ";
$fields = array_map('trim', explode(",", $csvRow));
print_r($fields);
?>

The output is clean, whitespace-free values:

Array
(
    [0] => Jane
    [1] => Doe
    [2] => [email protected]
)

explode() also pairs naturally with list() destructuring to pull named parts out of a string:

<?php
$date = "2026-06-21";
[$year, $month, $day] = explode("-", $date);
echo "Year: $year, Month: $month, Day: $day";
?>

Output:

Year: 2026, Month: 06, Day: 21

Gotchas

• The separator is literal, not a regex. explode("-", ...) splits on a hyphen, never a pattern. If you need a regular expression (for example, splitting on any run of whitespace), use preg_split() instead.
• You cannot split into individual characters with explode(). An empty separator raises a ValueError. To split a string into single characters, use str_split().
• Multiple adjacent delimiters create empty elements. explode(",", "a,,b") returns ["a", "", "b"]. Filter them out with array_filter() if you don't want them.
• No separator found? You still get a valid array — a single-element array holding the whole string — so you can safely index [0].

Related functions

• implode() / join() — the reverse: join an array into a string.
• str_split() — split a string into fixed-length chunks (or characters).
• preg_split() — split using a regular expression.
• substr() — extract part of a string by position.
• trim() — clean whitespace from each piece after exploding.

Practice