array_map('trim', [' wallace ', ' bacco ', ' guilherme ']);

['wallace', 'bacco', 'guilherme']

$arr = [' wallace ', ' bacco ', ' guilherme '];

foreach ($arr as &$value) $value = trim($value);

array_map(function ($v1, $v2, $v3) {
       echo $v1, $v2, $v3;
}, ['a', 'b', 'c'], [1, 2, 3], ['@', '!', '&']);

'a1@'
'b1!'
'c3&'