String split and explode in PHP - Step-by-Step Execution

Concept Flow - String split and explode

Start with string

↓

Choose delimiter

↓

Call explode(delimiter, string)

↓

Split string at each delimiter

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Create array of substrings

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Return array

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End

The string is split into parts wherever the delimiter appears, creating an array of substrings.

Execution Sample

PHP

<?php
$str = "apple,banana,cherry";
$arr = explode(",", $str);
print_r($arr);
?>

This code splits the string by commas and prints the resulting array.

Execution Table

Step	Action	Input String	Delimiter	Resulting Array
1	Start with string	apple,banana,cherry	,	N/A
2	Call explode function	apple,banana,cherry	,	N/A
3	Split string at each comma	apple,banana,cherry	,	["apple", "banana", "cherry"]
4	Return array	apple,banana,cherry	,	["apple", "banana", "cherry"]

💡 All parts split by delimiter are collected into the array and returned.

Variable Tracker

Variable	Start	After explode	Final
$str	"apple,banana,cherry"	"apple,banana,cherry"	"apple,banana,cherry"
$arr	undefined	array("apple", "banana", "cherry")	array("apple", "banana", "cherry")

Key Moments - 3 Insights

Why does explode return an array instead of a string?

Because explode splits the original string into multiple parts at each delimiter, it returns all parts as an array, not a single string. See execution_table step 3.

What happens if the delimiter is not found in the string?

If the delimiter is not found, explode returns an array with the whole string as the only element. This is because no splitting occurs.

Can the delimiter be more than one character?

Yes, the delimiter can be multiple characters, and explode will split wherever that exact sequence appears.

Visual Quiz - 3 Questions

Look at the execution_table, what is the resulting array after step 3?

A ["apple", "banana"]

B ["apple", "banana", "cherry"]

C ["apple,banana,cherry"]

D []

💡 Hint

Check the 'Resulting Array' column in step 3 of the execution_table.

According to variable_tracker, what is the value of $arr before calling explode?

A "apple,banana,cherry"

B array("apple", "banana", "cherry")

C undefined

D null

💡 Hint

Look at the 'Start' column for $arr in variable_tracker.

If the delimiter was changed to ";" and the string stayed the same, what would $arr contain?

A ["apple,banana,cherry"]

B ["apple", "banana", "cherry"]

C []

D [""]

💡 Hint

If delimiter not found, explode returns array with whole string as one element.

Concept Snapshot

explode(delimiter, string) splits string at each delimiter occurrence
Returns an array of substrings
If delimiter not found, returns array with original string
Delimiter can be multiple characters
Useful to break strings into parts easily

Full Transcript

This example shows how the PHP function explode splits a string into an array using a delimiter. Starting with the string 'apple,banana,cherry', we call explode with ',' as the delimiter. The function finds each comma and splits the string into parts: 'apple', 'banana', and 'cherry'. These parts are collected into an array and returned. The variable $arr holds this array after explode runs. If the delimiter is not found, explode returns an array with the whole string as one element. The delimiter can be more than one character. This process helps break strings into manageable pieces for further use.