$var = 123;
$str = "This is a string with number $var";
$var = 123;
$str = "This is a string with number " . $var;
$var = 123;
$str = sprintf("This is a string with number %d", $var);
$arr = array('Hello', 'World');
$str = implode(' ', $arr);
$arr = array('Hello', 'World');
$str = json_encode($arr);
$arr = array('Hello', 'World');
$str = serialize($arr);
