Generator return values in PHP - Step-by-Step Execution

Concept Flow - Generator return values

Start Generator Function

↓

Yield values one by one

↓

Generator finishes

↓

Return value captured

↓

Access return value via getReturn()

↓

End

The generator yields values step-by-step, then returns a final value which can be accessed after iteration ends.

Execution Sample

PHP

<?php
function gen() {
  yield 1;
  yield 2;
  return 3;
}
$g = gen();
foreach ($g as $val) {
  echo $val . "\n";
}
echo "Return: " . $g->getReturn() . "\n";
?>

This code yields two values from the generator, then returns a final value accessible after iteration.

Execution Table

Step	Action	Yielded Value	Generator State	Output
1	Start generator and yield first value	1	Running	Print 1
2	Yield second value	2	Running	Print 2
3	Generator reaches return statement	None	Finished	No yield, iteration ends
4	Access return value via getReturn()	3	Finished	Print Return: 3

💡 Generator finished after return statement, iteration stops, return value accessed separately

Variable Tracker

Variable	Start	After Step 1	After Step 2	After Step 3	Final
$val	undefined	1	2	undefined	undefined
$g->getReturn()	undefined	undefined	undefined	3	3

Key Moments - 2 Insights

Why does the return value not appear in the foreach loop output?

The foreach loop only outputs values yielded by yield statements (see steps 1 and 2). The return value is not yielded, so it appears only when accessed with getReturn() after iteration ends (step 4).

What happens when the generator hits the return statement?

At step 3, the generator finishes and stops yielding values. The return value is stored internally and can be retrieved later with getReturn(), but it does not produce output during iteration.

Visual Quiz - 3 Questions

Look at the execution table, what is the generator state after yielding the second value?

A Running

B Finished

C Paused

D Not started

💡 Hint

Check the 'Generator State' column at Step 2 in the execution_table.

At which step does the generator stop yielding values?

A Step 1

B Step 2

C Step 3

D Step 4

💡 Hint

Look for the step where 'Generator State' changes to 'Finished' and no value is yielded.

If the return statement was removed, what would happen to the output at step 4?

A It would print the last yielded value

B It would print nothing or null

C It would print 0

D It would cause an error

💡 Hint

Without a return, getReturn() returns null or nothing after iteration ends.

Concept Snapshot

PHP Generators yield values stepwise using yield.
When generator ends, it can return a value with return.
Return value is NOT yielded, so foreach won't show it.
Use getReturn() on generator after iteration to get it.
Useful to send final result after yielding sequence.

Full Transcript

This example shows a PHP generator function that yields two values, 1 and 2, then returns 3. The foreach loop prints the yielded values 1 and 2. After the loop finishes, the generator is done, and the return value 3 is accessed using getReturn(). The return value does not appear during iteration because only yield produces output. The generator state changes from running to finished when the return statement is reached. This allows the program to get a final result from the generator after all values have been yielded.