Memory efficiency with generators 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 5.

PHP

<?php
function numbers() {
    for ($i = 1; $i <= 5; $i++) {
        yield [1];
    }
}
?>

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

A$count

B$j

C$num

D$i

Attempts:

3 left

💡 Hint

Common Mistakes

Using a variable not defined in the loop.

Trying to return instead of yield.

The generator yields the current number $i in the loop.

2fill in blank

medium

Complete the code to iterate over the generator and print each value.

PHP

<?php
foreach (numbers() as [1]) {
    echo $value . "\n";
}
?>

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

A$value

B$item

C$num

D$element

Attempts:

3 left

💡 Hint

Common Mistakes

Using a different variable name in the loop body than in the foreach.

Forgetting the $ sign.

The foreach loop variable should match the variable used inside the loop to print.

3fill in blank

hard

Fix the error in the generator function to yield squares of numbers from 1 to 5.

PHP

<?php
function squares() {
    for ($i = 1; $i <= 5; $i++) {
        yield [1];
    }
}
?>

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

A$i * $i

B$i + $i

Cpow($i, 3)

D$i / 2

Attempts:

3 left

💡 Hint

Common Mistakes

Using addition or division instead of multiplication.

Using cube instead of square.

To yield squares, multiply $i by itself.

4fill in blank

hard

Fill both blanks to create a generator that yields only even numbers from 1 to 10.

PHP

<?php
function evenNumbers() {
    for ($i = 1; $i <= 10; $i++) {
        if ($i [1] 2 == 0) {
            yield [2];
        }
    }
}
?>

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

A%

B$i

C==

D$num

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong operator for modulus.

Yielding a variable not defined.

Use modulus operator % to check evenness and yield $i.

5fill in blank

hard

Fill all three blanks to create a generator that yields keys and values from an array where values are greater than 10.

PHP

<?php
function filterArray($arr) {
    foreach ($arr as [1] => [2]) {
        if ([2] > 10) {
            yield [1] => [2];
        }
    }
}
?>

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

A$key

B$value

C$val

D$k

Attempts:

3 left

💡 Hint

Common Mistakes

Using inconsistent variable names.

Yielding only values without keys.

Use $key and $value for keys and values; yield key => value.