Memory usage is unaffected by using a symbolic link instead of cyclic direct assignment

symbolic-links-vs-direct-assignment-in-cycle.php

<?php

/* There is no point in using symbolic links instead of just assigning values in the case below. */

// Run this on console or use ob_flush()!

echo "Before: " . round(memory_get_peak_usage(true)/1024/1024, 2) . " Mb\n";

// Never less than 2 mb at start

$string = str_repeat('a', 1000000); // Still 2 Mb

$array = array_fill(0, 100000, [ 'id' => 1 ]); // 6 Mb

foreach ($array as $row) { // &$row increases it from 6 to 10 Mb
    // No actions with $row increase usage.
    // Any action with &$row  increases to 46 Mb
    // $row['rand'] = rand();

    // $row['value'] = &$string;
    // $row['value'] = $string;
    // No difference between $string and &$string
    // $a2[] = $row; // 12 Mb (+6 Mb)
    // $row['id']; // No effect
    // $a2[] = []; // 12 Mb
    // $a2[] = ['id' => 1]; // 12 Mb
    // $a2[] = [ 'value' => $string ]; // 46 Mb
    // $a2[] = [ 'id' => rand() ];// 46 Mb
}

echo "After: " . round(memory_get_peak_usage(true)/1024/1024, 2) . " Mb";