PHP Yield: Purpose & Benefits Explained

The yield keyword in PHP is used for generator functions, which convert a function into an iterable object that returns one value at a time instead of all values at once.

Generator functions use the “yield” keyword to produce values and pause the execution of the function while yielding values. When iterated again, the function will continue from where it paused last and generate the next value.

One advantage of using generator functions with yield is the ability to save memory space, as it does not generate all values at once, but rather generates them as needed. This is very useful when dealing with large amounts of data or when results need to be obtained step by step.

Here is an example of using yield:

function generateNumbers($start, $end) {
    for ($i = $start; $i <= $end; $i++) {
        yield $i;
    }
}

$numbers = generateNumbers(1, 10);

foreach ($numbers as $number) {
    echo $number . " ";
}

The output is: 1 2 3 4 5 6 7 8 9 10. In this example, the generateNumbers() function uses yield to generate all numbers from $start to $end, instead of returning an array all at once. We can then use a foreach loop to iterate and print each number.

In conclusion, the function of yield is to create an iterable object and generate a value each time it is iterated. It can save memory space and is very suitable for handling large amounts of data or situations where results need to be obtained gradually.