Generator function execution model in PHP - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a generator function that yields numbers from 1 to 3.

PHP

<?php
function numbers() {
    yield [1];
}

foreach (numbers() as $num) {
    echo $num . " ";
}
?>

Drag options to blanks, or click blank then click option'

A1

B5

C0

D3

Attempts:

3 left

💡 Hint

Common Mistakes

Yielding 0 instead of 1.

Yielding the last number directly without starting from 1.

The generator yields the number 1 first. Using yield 1; starts the sequence.

2fill in blank

medium

Complete the code to yield numbers from 1 to 3 using a loop inside the generator.

PHP

<?php
function numbers() {
    for ($i = 1; $i <= [1]; $i++) {
        yield $i;
    }
}

foreach (numbers() as $num) {
    echo $num . " ";
}
?>

Drag options to blanks, or click blank then click option'

A5

B1

C3

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Using 5 instead of 3, which yields extra numbers.

Using 0 which yields no numbers.

The loop should run until 3 to yield numbers 1, 2, and 3.

3fill in blank

hard

Fix the error in the generator function to correctly yield values.

PHP

<?php
function gen() {
    [1] 1;
    [1] 2;
    [1] 3;
}

foreach (gen() as $val) {
    echo $val . " ";
}
?>

Drag options to blanks, or click blank then click option'

Ayield

Breturn

Cecho

Dprint

Attempts:

3 left

💡 Hint

Common Mistakes

Using return instead of yield.

Using echo or print inside the generator.

In a generator, yield is used to produce values one at a time.

4fill in blank

hard

Fill both blanks to create a generator that yields squares of numbers from 1 to 4.

PHP

<?php
function squares() {
    for ($i = 1; $i [1] 4; $i++) {
        yield $i [2] 2;
    }
}

foreach (squares() as $sq) {
    echo $sq . " ";
}
?>

Drag options to blanks, or click blank then click option'

A<=

B**

C*

D>

Attempts:

3 left

💡 Hint

Common Mistakes

Using * instead of ** which multiplies but does not square.

Using < which excludes 4.

The loop runs while $i is less than or equal to 4, and squares are calculated using the exponent operator **.

5fill in blank

hard

Fill all three blanks to create a generator that yields only even numbers from 2 to 6.

PHP

<?php
function evens() {
    for ($n = [1]; $n [2] 6; $n += 2) {
        yield [3];
    }
}

foreach (evens() as $even) {
    echo $even . " ";
}
?>

Drag options to blanks, or click blank then click option'

A1

B<=

C$n

D2

Attempts:

3 left

💡 Hint

Common Mistakes

Starting from 1 which is odd.

Using < which excludes 6.

Yielding a fixed number instead of $n.

The loop starts at 2, runs while $n is less than or equal to 6, and yields $n each time.