return -- exit a procedure
Introductionreturn(x) terminates the execution of a
procedure and returns x.
Call(s)return(x)
Parametersx |
- | any MuPAD object |
Returnsx.
Related
Functions
DetailsAlternatively, the call return(x) inside a
procedure leads to immediate exit from the procedure: x is
evaluated and becomes the return value of the procedure. Execution
proceeds after the point where the procedure was invoked.
x may be an expression
sequence, i.e., calls such as return(x1, x2,
...) are allowed.return() returns the void object of type
DOM_NULL.return is a function, not a keyword. A
statement such as return x; works in the programming
language C, but causes a syntax error in MuPAD.return(x)
just returns x.return is a function of the system kernel.
Example
1This example shows the implementation of a maximum
function (which, in contrast to the system function max, accepts only two arguments). If
x is larger than y, the value of
x is returned and the execution of the procedure
mymax stops. Otherwise,
return(x) is not called. Consequently,
y is the last evaluated object defining the return
value:
>> mymax := proc(x : Type::Real, y : Type::Real)
begin
if x > y then
return(x)
end_if;
y
end_proc:
>> mymax(3, 2), mymax(4, 5)
3, 5
>> delete mymax:
Example
2return() returns the void
object:
>> f := x -> return(): type(f(anything))
DOM_NULL
>> delete f:
Example
3If return is called on the interactive
level, the evaluated arguments are returned:
>> x := 1: return(x, y)
1, y
>> delete x: