FreeMat: RETURN Return From Function

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RETURN Return From Function

Section: Flow Control

# Usage

The `return` statement is used to immediately return from a function, or to return from a `keyboard` session. The syntax for its use is

      return

Inside a function, a `return` statement causes FreeMat to exit the function immediately. When a `keyboard` session is active, the `return` statement causes execution to resume where the `keyboard` session started.

# Example

In the first example, we define a function that uses a `return` to exit the function if a certain test condition is satisfied.

         return_func.m

    function ret = return_func(a,b)
      ret = 'a is greater';
      if (a > b)
        return;
      end
      ret = 'b is greater';
      printf('finishing up...\n');

Next we exercise the function with a few simple test cases:

    --> return_func(1,3)
    finishing up...

    ans =
    b is greater
    --> return_func(5,2)

    ans =
    a is greater

In the second example, we take the function and rewrite it to use a `keyboard` statement inside the `if` statement.

         return_func2.m

    function ret = return_func2(a,b)
      if (a > b)
         ret = 'a is greater';
         keyboard;
      else
         ret = 'b is greater';
      end
      printf('finishing up...\n');

Now, we call the function with a larger first argument, which triggers the `keyboard` session. After verifying a few values inside the `keyboard` session, we issue a `return` statement to resume execution.

    --> return_func2(2,4)
    finishing up...

    ans =
    b is greater
    --> return_func2(5,1)
    [return_func2,4]--> ret

    ans =
    a is greater
    [return_func2,4]--> a

    ans =
     5

    [return_func2,4]--> b

    ans =
     1

    [return_func2,4]--> return
    finishing up...

    ans =
    a is greater