Return values in PHP - Step-by-Step Execution

Concept Flow - Return values

Function called

↓

Execute function code

↓

Return value reached

↓

Return value sent back

↓

Function call replaced by return value

When a function is called, it runs its code and sends back a value using return. The calling code receives this value.

Execution Sample

PHP

<?php
function add($a, $b) {
  return $a + $b;
}
$result = add(2, 3);
echo $result;
?>

This code defines a function that adds two numbers and returns the sum, then prints the result.

Execution Table

Step	Action	Evaluation	Result
1	Call add(2, 3)	Parameters: a=2, b=3	Function starts
2	Calculate a + b	2 + 3	5
3	Return 5	Return statement reached	5 sent back to caller
4	Assign return to $result	$result = 5	$result holds 5
5	echo $result	Print $result	Output: 5

💡 Function ends after return; value 5 sent back and printed

Variable Tracker

Variable	Start	After Step 1	After Step 4	Final
$a	undefined	2	undefined	undefined
$b	undefined	3	undefined	undefined
$result	undefined	undefined	5	5

Key Moments - 3 Insights

Why does the function stop running after the return statement?

Because return sends a value back and immediately ends the function execution, as shown in step 3 of the execution_table.

What happens to the return value after the function finishes?

The return value replaces the function call in the code, so $result gets assigned the returned value, as seen in step 4.

Can code after return inside the function run?

No, code after return is ignored because return ends the function immediately, shown by no steps after step 3 inside the function.

Visual Quiz - 3 Questions

Look at the execution_table, what value does the function add return at step 3?

A 2

B 5

C 3

D Undefined

💡 Hint

Check the 'Result' column in step 3 of the execution_table.

At which step does the variable $result get its value?

A Step 2

B Step 1

C Step 4

D Step 5

💡 Hint

Look at the 'Action' column where $result is assigned in the execution_table.

If the return statement was removed, what would happen to the output?

A Output would be empty or nothing

B Output would be 0

C Output would be 5

D No output or error

💡 Hint

Without return, the function returns nothing, so $result is empty; see variable_tracker for $result values.

Concept Snapshot

Return values in PHP:
- Use 'return' to send a value back from a function.
- Function stops running after return.
- The returned value replaces the function call.
- Assign return to variables to use the result.
- Code after return inside function does not run.

Full Transcript

This example shows how a PHP function returns a value. When add(2, 3) is called, the function runs with parameters a=2 and b=3. It calculates 2 + 3 and returns 5. The return statement ends the function immediately. The returned value 5 is assigned to $result. Then echo prints 5. Variables $a and $b hold 2 and 3 during the function. $result gets 5 after the function returns. Code after return is not executed. This is how return values work in PHP functions.