So...CS people...how can a function return value be on the lhs of an assignment?

[beer]

This is a question for a test I have coming up tonight:

Problem 4. Suppose x is an array of n double values declared by the following statements.
double x[100];
int n;
Write the definition of the function Maximum() that will put the component with the maximum
value to 17.1 with the call
Maximum(x, n) = 17.1;
You may assume 0 < n < 101. In the case of ties for the maximum value, the component with
the smallest subscript should be changed.

The only way that I have been able that this wuold work was if I had Maximum() return a pointer and then dereference it to assign 17.1 to it. But I can't do that. Obviously I can't just return a double, I have to return a double pointer, but when I return the pointer to the highest value it fails to compile with the error, 'not an lvalue.' Is this possible?

 

[gopunk]

C, C++... overload the equals sign operator? dunno.... what language?

 

[agnitrate]

I'm not sure if that's even possible. Kinda pointless even if it was though IMHO.

-silver

 

[beer]

Originally posted by: agnitrate
I'm not sure if that's even possible. Kinda pointless even if it was though IMHO.

-silver

Our test are all about pointless stuff. That's the point! (pun intended)

This is in C++. Sorry, forgot to specify.

 

[DaveSimmons]

A function can return a reference, a pointer, or a value / object.

 

[beer]

Originally posted by: DaveSimmons
A function can return a reference, a pointer, or a value / object.

Of which all give me the error, 'not an lvalue' when I compile. Which means they belong on the rhs of an assignment, not the lhs, which this problem is asking.

 

[DaveSimmons]

Two of them will. Just tried the third and it compiled without errors.

edit: Why not post your code skeleton for the two types, pehaps you're making a mistake in your function declaration.

 

[TheBoyBlunder]

You know you game too much when you see "CS" and think Counterstrike.

 

[Venix]

You have to return a reference instead of a pointer. If your function already works when you do this: *Maximum(x,n) = 17.1, all you have to do is change it to return a double&, and then dereference the pointer to the max value before returning it.

 

[DaveSimmons]

Originally posted by: Venix
You have to return a reference instead of a pointer. If your function already works when you do this: *Maximum(x,n) = 17.1, all you have to do is change it to return a double&, and then dereference the pointer to the max value before returning it.

Yes, if beer got an error compiling there's something wrong with his function declaration.

 

[johnjbruin]

in c++.. overload ( ) to [ ] to make the code cryptic... it will work but is really dumb
in any other language... i have no f'in idea