Messing around yesterday, I decided to make my first 'game' (essentially just a dot moved by the player to avoid other dots). Anyways, I used a for loop to have it create and update new enemies whenever appropriate.

            if( iEnemy == 1 )   //Checks to see if it's time for enemies to exist.
            {
                for( iRe2 = 0 ; iRe2 == n; ++iRe2)  //Runs through all enemy coordinates.
                {
                    if( mouse_x > iEnemyX[iRe2] ) ++iEnemyX[iRe2];
                    if( mouse_x < iEnemyX[iRe2] ) --iEnemyX[iRe2];
                    if( mouse_y > iEnemyY[iRe2] ) ++iEnemyY[iRe2];
                    if( mouse_y < iEnemyY[iRe2] ) --iEnemyY[iRe2];

                    circle( buffer, iEnemyX[iRe2], iEnemyY[iRe2], 5, makecol( 255, 0, 0 )); //Draws all enemies.
                }
            }

I know for a fact that the issue is with the for loop, and I can comment it out and everthing works fine. Once.

The integer 'n' is increased whenever a new enemy should be added. In my head, this loop should create and update enemies as necessary, but as it is (without commenting anything out ) it seems to keep anything from happening. No enemies are created.

If anyone could help me out, that'd be great.

The second term of for() is the required condition to run the body {}. As soon as it evaluates to false, the body is skipped and the program continues.

You probably want iRe2<n or iRe2<=n

Well I feel dumb. I thought it was the exit condition.

Works perfectly. All thanks to the magic of basic knowledge.

Yeah, it's the "positive" condition to meet, so it's consistent with while()

I've always hated "for" loops, they're just while loops with some inbuilt comfortable extra stuff... but then again, that's what it all is..

But for loops are amazing! They're like using switch() && case rather than a bunch of if conditions.

I believe it's a matter of taste .

Guess so hehe

You don't really appreciate the comfort of C for loops until you've had to use FORTRAN DO loops. Personally I've lately become a big fan of Perl's foreach loop.

And the "foreach" style is mostly dpereciated. the for loop does the same thing. one keyword, multiple syntaxes

You mean I can write "for" instead of "foreach"? I know, but I find "foreach" easier to read when I want a "foreach" loop. I don't mind typing the extra four characters at all, unlike Larry (according to my llama).

On the note of "switch()" statements, I learned in my class that they can actually be more optimized than a bunch of if..then()'s!

Using gcc/g++, if you look at (and understand) the disassembled code for your program, it actually tweaks your code to use a lookup table if you have a lot of case... conditions:

Example 1

...gets translated into...

EDIT: Understand, that this isn't assembly that you're looking at, but rather a pseudo-code written in a "kinda" C format so those of a.cc who don't natively speak ASM could figure out what's going on.

So if you put in a number < 100, it overflows (underflows?) to become a very large value, which is > 6 (which is how many "case:" statements you have in your code). Also, notice that since there is no "101" or "105", they are still accounted-for in the "jumpTable" (by putting in locations of "loc_def" -- which is at the end of the switch() statement). It's that "default:" that turns everything else into "result = 0", so that's where it jumps to.

Anyway, that's just something I picked up from one of these courses I'm taking. As I understand it, unless you only have one or two "...else if..."s in your code, a switch statement is more optimal to have.

If you use &&label in the jumptable, and goto **table[index];, it should work in GCC.

I thought computed goto was a DJGPPism? great anyway.