int(1)
array(1) {
  [0]=>
  string(7) "Hello, "
}
int(0)
array(0) {
}
int(1)
array(2) {
  [0]=>
  string(23) "[*], this is \ a string"
  [1]=>
  string(18) "this is \ a string"
}
int(1)
array(1) {
  [0]=>
  array(2) {
    [0]=>
    string(18) "this is \ a string"
    [1]=>
    int(19)
  }
}
int(0)
array(0) {
}