note 99280 modified in control-structures.foreach by danbrown

Your last value changes after use of references. <?php $arr = array(' one ', ' two ', ' tree ', ' four ', ' five '); print_r($arr); foreach ($arr as &$str) $str = trim($str); print_r($arr); foreach ($arr as $str) echo $str . "\n"; print_r($arr); ?> Array ( Array ( one Array ( [0] => one [0] => one two [0] => one [1] => two [1] => two tree [1] => two [2] => tree [2] => tree four [2] => tree [3] => four [3] => four four [3] => four [4] => five [4] => five [4] => four ) ) ) <?php $arr = array(' one ', ' two ', ' tree ', ' four ', ' five '); foreach ($arr as &$str) $str = trim($str); foreach ($arr as $str) { print_r($arr); echo $str . "\n"; } print_r($arr); ?> [0] => one => one => one => one => one => one [1] => two => two => two => two => two => two [2] => tree => tree => tree => tree => tree => tree [3] => four => four => four => four => four => four [4] => one => two => tree => four => four => four tested in PHP 5.2.4 and PHP 5.3.0 --was-- Your last value changes after use of references. $arr = array(' one ', ' two ', ' tree ', ' four ', ' five '); print_r($arr); foreach ($arr as &$str) $str = trim($str); print_r($arr); foreach ($arr as $str) echo $str . "\n"; print_r($arr); Array ( Array ( one Array ( [0] => one [0] => one two [0] => one [1] => two [1] => two tree [1] => two [2] => tree [2] => tree four [2] => tree [3] => four [3] => four four [3] => four [4] => five [4] => five [4] => four ) ) ) $arr = array(' one ', ' two ', ' tree ', ' four ', ' five '); foreach ($arr as &$str) $str = trim($str); foreach ($arr as $str) { print_r($arr); echo $str . "\n"; } print_r($arr); [0] => one => one => one => one => one => one [1] => two => two => two => two => two => two [2] => tree => tree => tree => tree => tree => tree [3] => four => four => four => four => four => four [4] => one => two => tree => four => four => four tested in PHP 5.2.4 and PHP 5.3.0 http://php.net/manual/en/control-structures.foreach.php