Array search functions in PHP - Step-by-Step Execution

Concept Flow - Array search functions

Start with array and search value

↓

Choose search function

↓

Function checks each element

↓

Match found

↓

Return key/index

↓

End

The search function checks each element in the array for a match and returns the key/index if found, otherwise returns false.

Execution Sample

PHP

<?php
$array = ["apple", "banana", "cherry"];
$search = array_search("banana", $array);
echo $search;
?>

This code searches for "banana" in the array and prints its index.

Execution Table

Step	Array Element	Search Value	Match?	Action	Return Value
1	"apple"	"banana"	No	Check next element	N/A
2	"banana"	"banana"	Yes	Return index 1	1
3	N/A	N/A	N/A	Stop search	1

💡 Search stops after finding "banana" at index 1.

Variable Tracker

Variable	Start	After Step 1	After Step 2	Final
$array	["apple", "banana", "cherry"]	["apple", "banana", "cherry"]	["apple", "banana", "cherry"]	["apple", "banana", "cherry"]
$search	null	null	1	1

Key Moments - 2 Insights

Why does array_search return 1 instead of true?

array_search returns the key/index of the found element, not a boolean. See execution_table step 2 where it returns index 1.

What happens if the search value is not in the array?

array_search returns false if no match is found, as shown in the exit_note and would continue checking all elements.

Visual Quiz - 3 Questions

Look at the execution table, what is the return value at step 2?

A true

B false

C 1

D null

💡 Hint

Check the 'Return Value' column at step 2 in the execution_table.

At which step does the search find a match?

A Step 1

B Step 2

C Step 3

D No match found

💡 Hint

Look at the 'Match?' column in the execution_table.

If the search value was "orange", what would array_search return?

A false

B 0

C null

D 3

💡 Hint

Recall from key_moments that array_search returns false if no match is found.

Concept Snapshot

array_search(value, array) searches for value in array.
Returns the key/index if found.
Returns false if not found.
Checks elements one by one until match or end.
Useful to find position of a value in an array.

Full Transcript

This visual shows how PHP's array_search function works. It starts with an array and a value to find. The function checks each element in order. If it finds the value, it returns the key or index of that element. If it does not find the value, it returns false. In the example, searching for "banana" returns 1 because "banana" is at index 1. The variable $search changes from null to 1 after the match. If the value was not found, $search would be false. This helps you find where a value is in an array.