Online PHP editor | output for I5FHp

<?php function wordsToArr2($str) { $words = [$str]; while ($pos =strpos ( $str , ' ')) { $str=substr($str,($pos+1)); $words[] =$str; } return $words; } function wordsToArr3($str) { $base = array_reverse(explode(' ', $str)); $words = [$placeholder = array_shift($base)]; foreach ($base as $word) { $words[] = $placeholder = $word . ' ' . $placeholder; } return array_reverse($words); } function wordsToArr4($str) { $base = explode(' ', $str); end($base); $l = key($base); $words = [$placeholder = $base[$l--]]; for ($i=$l; $i>=0;$i--) { $words[] = $placeholder = $base[$i] . ' ' . $placeholder; } return array_reverse($words); } function wordsToArr5($str) { $base = str_word_count($str, 1); $l = count($base)-1; $words = [$placeholder = $base[$l--]]; for ($i=$l; $i>=0;$i--) { $words[] = $placeholder = $base[$i] . ' ' . $placeholder; } return array_reverse($words); } function wordsToArr2($str) { $words = []; $ph = ''; while ($ph !== $str) { $words[] = $ph = substr($ph, strpos( $str , ' ', -1)); } return $words; } function bench($callback, $arg, $runs = 100) { $t = 0; $now = microtime(true); for ($i=0; $i<$runs; $i++) { $callback($arg); } $t += (microtime(true) - $now); return [number_format($t, 8), $i]; } $sentence = 'The quick brown fox jumps over the lazy dog'; $ph = $sentence; $ph = substr($ph, strpos($ph , ' ', -1)); var_dump($ph); exit; list($t, $i) = bench('wordsToArr2', $sentence); echo 'strpos '. $i .' times in: ' . $t . '/sec' . PHP_EOL; list($t, $i) = bench('wordsToArr3', $sentence); echo 'concat '. $i .' times in: ' . $t . '/sec' . PHP_EOL; list($t, $i) = bench('wordsToArr4', $sentence); echo 'end/key '. $i .' times in: ' . $t . '/sec' . PHP_EOL; list($t, $i) = bench('wordsToArr5', $sentence); echo 'count-- '. $i .' times in: ' . $t . '/sec' . PHP_EOL;