y++

[ARMAS]

what's the difference between "y++" and "y=y+1"?

 

[Richard Bos]

what's the difference between "y++" and "y=y+1"?

Ignoring stupid homework niggles, nothing whatsoever.

Richard

 

[Chris Dollin]

Ignoring stupid homework niggles, nothing whatsoever.

Um ... does

The value of the expression `y++` is the original
value of `y`, while the value of the expression `y=y+1`
is the new value of `y`.

count as a "stupid homework niggle"?

 

[Richard Bos]

Um ... does

The value of the expression `y++` is the original
value of `y`, while the value of the expression `y=y+1`
is the new value of `y`.

count as a "stupid homework niggle"?

Yes. _As written_, those two do the same thing. _In context_ they might
do completely different things - you might, for example, also #define y
call_a_complex_function(pointer_to_binary_tree) - but outside of
homework problems or job applications, I expect such a context to be
given with the problem.

Richard

 

[Richard Tobin]

Um ... does

The value of the expression `y++` is the original
value of `y`, while the value of the expression `y=y+1`
is the new value of `y`.

count as a "stupid homework niggle"?

[/QUOTE]

Yes. _As written_, those two do the same thing. _In context_ they might
do completely different things - you might, for example, also #define y
call_a_complex_function(pointer_to_binary_tree) - but outside of
homework problems or job applications, I expect such a context to be
given with the problem.

_As written_, they do the same thing as foo=76. _In context_ - for
example if the variable y is used somewhere else - they may do
different things.

-- Richard

 

[Chris Dollin]

Yes.

OK. You niggle more than I, then.

_As written_, those two do the same thing. _In context_ they might
do completely different things - you might, for example, also #define y
call_a_complex_function(pointer_to_binary_tree) - but outside of
homework problems or job applications, I expect such a context to be
given with the problem.

I find this argument uncompelling, since the value of an expression
is an important property of it, and using the value of an expression
a very common context.

I note that the expressions `y++` and `(y++, 0)` do the same thing
as written, but would hesitate to describe their differences as
a niggle.

 

[Mike Wahler]

what's the difference between "y++" and "y=y+1"?

A program that will tell you the difference
between the values of the two expressions
y++ and y=y+1 :

#include <math.h>
#include <stdio.h>

int main()
{
int init = 0;
int y = init;
int a = y++;
y = init;
int b = y = y + 1;

printf("%d\n", abs(a - b);
return 0;
}

-Mike

 

[Richard Heathfield]

Mike Wahler said:

printf("%d\n", abs(a - b);
return 0;
}

-Mike

Mike - could you use this? )


No charge.