Unique way to generate array intersection and union using PHP generator

The steps to use a generator to generate array intersections and unions are as follows: define a generator function, use yield to return a value and remember its current state. A generator that creates array intersections, using the array_intersect() function to return a new array containing the elements in the intersection. Likewise, create a generator for the union of arrays, using the array_merge() function to return a new array containing all the elements in both arrays. Use a generator variable to iterate over the intersection or union, getting each element.

A unique way to generate array intersections and unions using PHP generators

In PHP, a generator is a Special functions for generating sequence data. They are ideal for use in situations where large data sets need to be traversed or results calculated lazily. This article shows a unique way of using generators to generate array intersections and unions.

Generator syntax

Generator functions are defined in PHP using the yield keyword. This keyword allows a function to return a value and remember its current state without interrupting execution.

function myGenerator() {
    yield 1;
    yield 2;
    yield 3;
}

Array intersection generator

To create a generator for array intersection, you can use the array_intersect() function, which returns an array containing the intersection A new array of concentrated elements. The generator version is as follows:

function intersectGenerator(array $arr1, array $arr2): Generator {
    foreach ($arr1 as $k => $v) {
        if (in_array($v, $arr2, true)) {
            yield $v;
        }
    }
}

Array union generator

Similarly, the generation of array union can be created using the array_merge() function device. This function returns a new array containing all elements in both arrays (including duplicate elements). The generator version is as follows:

function mergeGenerator(array $arr1, array $arr2): Generator {
    foreach ($arr1 as $v) {
        yield $v;
    }
    foreach ($arr2 as $v) {
        if (!in_array($v, $arr1, true)) {
            yield $v;
        }
    }
}

Practical example

Consider the following example:

$arr1 = [1, 2, 3, 4, 5];
$arr2 = [3, 4, 5, 6, 7];

$intersection = intersectGenerator($arr1, $arr2);
$union = mergeGenerator($arr1, $arr2);

foreach ($intersection as $value) {
    echo $value . " ";
}
echo "\n";

foreach ($union as $value) {
    echo $value . " ";
}

This will print out:

3 4 5
1 2 3 4 5 6 7

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