Split, explode

In PHP the explode() function is used for splitting strings on a delimiter. It takes the parts of a string and separates them into an array.

With a delimiter, we specify where the separations occur. Usually we separate based on a character like a comma or newline. We can loop over the resulting array with foreach.

Example

To begin we specify an input string that contains 3 words, and 2 commas separating the words. This is the string we want to split apart.

$value = "one,two,three";

// Separate string based on comma.
$result = explode(",", $value);

// Loop over result and print elements.
foreach ($result as $r) {
    print($r . "\n");
}
one
two
three

Maximum array size

It is possible to specify the maximum array size we want to receive from explode. We specify a limit argument as the third parameter to explode.

$value = "a,b,c,d";

// Split into two elements.
$result = explode(",", $value, 2);
var_dump($result);
array(2) {
  [0]=>
  string(1) "a"
  [1]=>
  string(5) "b,c,d"
}

Explode, implode

In PHP the "split" and "join" functions are called explode and implode, and with them we can round-trip our data. We can get the original string back after splitting it apart.

$value = "blue,red,green";
var_dump($value);

// Explode the string, and then implode it to get the original back.
$result = explode(",", $value);
$value = implode(",", $result);

var_dump($value);
string(14) "blue,red,green"
string(14) "blue,red,green"

Str_split

There is a string split function in PHP, but it works to separate a string into fixed-sized chunks of a certain length. It does not act upon delimiters.

$value = "aaaaaaa";
// Use split to get "chunks" from the string.
// Split in PHP does not use delimiters.
$result = str_split($value, 3);
var_dump($result);
array(3) {
  [0]=>
  string(3) "aaa"
  [1]=>
  string(3) "aaa"
  [2]=>
  string(1) "a"
}

By exploding and imploding strings, we convert strings to arrays and back to strings in PHP. These functions are named in an unusual way, but they perform standard split and join operations.