Help with for loop, please.

**someoney3000** · 10-14-2009

I have a cpp program that I'm having trouble with; particularly in the for loop.

Code:

void myInit() {

        glClearColor(0, 0, 0, 0);
        glShadeModel(GL_SMOOTH);

        //init aliens, took me waaaay too long to figure this out
        head_alien = NULL;
/*      for (int i = 0; i < row_aliens; i++) {
                for (int j = 0; j < col_aliens; j++) {

                        aliens current;
                        current.x = al_init_x + j * (alien_size + alien_spacing);
                        current.y = al_init_y + i * (alien_size + alien_spacing);
                        current.next = head_alien;
                        head_alien = &current;

                }
        }
*/
        head_bullet = NULL;

        cout << "\nNothing yet...\n";
        cout.flush();

}       //end myInit

I narrowed down the problem to that commented out for loop. If I left it in, I get errors like "error: expected primary-expression before '=' token" for the first for loop amongst others. Am I treating for loops incorrectly for c++? It worked this way in a c program I had. Or is the problem somewhere else entirely?

Also, all the head_alien, row_aliens, col_aliens, etc are either #define or global variables.

**tabstop** · 10-14-2009

That depends on which line has the error in it. But I like guessing, so here I go: you did this

Code:

#define row_aliens = 10

instead of

Code:

#define row_aliens 10

**someoney3000** · 10-14-2009

Originally Posted by someoney3000

Originally Posted by tabstop

That depends on which line has the error in it. But I like guessing, so here I go: you did this

Code:

#define row_aliens = 10

instead of

Code:

#define row_aliens 10

Wow, you're absolutely right! I did do that wrong, thanks!

So I went back and changed all of them, but I'm still getting the same errors.

Code:

g++ -lglut galaxian.cpp 
galaxian.cpp: In function 'void myInit()':
galaxian.cpp:78: error: expected primary-expression before ';' token
galaxian.cpp:78: error: expected ')' before ';' token
galaxian.cpp:78: error: name lookup of 'i' changed for ISO 'for' scoping
galaxian.cpp:78: note: (if you use '-fpermissive' G++ will accept your code)
galaxian.cpp:78: error: expected ';' before ')' token
galaxian.cpp:268: error: expected '}' at end of input

Judging from the errors in my very limited experience, I was expecting that I was missing a } or ) somewhere. But I simply commented out the for loop, then all the error goes away. That's why I think it's somewhere in the for loop. Is anyone seeing an error?

Ah, right, line 78 is the beginning of that for loop.

Ah, nevermind. I'm a retard.

You're right that I did the #define incorrectly

I did something like this:

Code:

#define row_aliens 10;

That semicolon is at fault.

Thanks! It seems I owe you twice in one day!

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Help with for loop, please.