是否可以在iOS中调用子函数？

Question

我们有以下递归函数：

parent "function"
  {
  if (main condition)
  {
  if (condition1) call a child "function";
  if (condition2) call a child "function";
  if (condition3) call a child "function";
  if (condition4) call a child "function";
  } Else {
  exit from child function and return to the position in which she had been called in the parent function;
  }
  }

如何实施？