- substr: documentation ( source)
- array_map: documentation ( source)
- array_slice: documentation ( source)
- print_r: documentation ( source)
- array_unique: documentation ( source)
- range: documentation ( source)
- md5: documentation ( source)
<?php
$hashes = array_map(function ($num) { return substr(md5($num), 0, 8); }, range(0, 100000));
print_r(array_slice($hashes, 0, 10));
if (array_unique($hashes) == $hashes) {
echo 'all unique';
} else {
echo 'collisions detected';
}