Can someone decipher the difference between this switch and an equivalent for?

[whatever]

This one works as intended:

		if (clu.raw.butsnum) {
			int i;
			for (i=0;i<clu.raw.butsnum;i++){
				if (clu.raw.buts[i] & RI_MOUSE_BUTTON_1_DOWN)
					Com_QueueEvent( 0, SE_KEY, K_MOUSE1, qtrue, 0, NULL );
				if (clu.raw.buts[i] & RI_MOUSE_BUTTON_2_DOWN)
					Com_QueueEvent( 0, SE_KEY, K_MOUSE2, qtrue, 0, NULL );
				if (clu.raw.buts[i] & RI_MOUSE_BUTTON_3_DOWN)
					Com_QueueEvent( 0, SE_KEY, K_MOUSE3, qtrue, 0, NULL );
				if (clu.raw.buts[i] & RI_MOUSE_BUTTON_4_DOWN)
					Com_QueueEvent( 0, SE_KEY, K_MOUSE4, qtrue, 0, NULL );
				if (clu.raw.buts[i] & RI_MOUSE_BUTTON_5_DOWN)
					Com_QueueEvent( 0, SE_KEY, K_MOUSE5, qtrue, 0, NULL );
				if (clu.raw.buts[i] & RI_MOUSE_BUTTON_1_UP)
					Com_QueueEvent( 0, SE_KEY, K_MOUSE1, qfalse, 0, NULL );
				if (clu.raw.buts[i] & RI_MOUSE_BUTTON_2_UP)
					Com_QueueEvent( 0, SE_KEY, K_MOUSE2, qfalse, 0, NULL );
				if (clu.raw.buts[i] & RI_MOUSE_BUTTON_3_UP)
					Com_QueueEvent( 0, SE_KEY, K_MOUSE3, qfalse, 0, NULL );
				if (clu.raw.buts[i] & RI_MOUSE_BUTTON_4_UP)
					Com_QueueEvent( 0, SE_KEY, K_MOUSE4, qfalse, 0, NULL );
				if (clu.raw.buts[i] & RI_MOUSE_BUTTON_5_UP)
					Com_QueueEvent( 0, SE_KEY, K_MOUSE5, qfalse, 0, NULL );
			}
			clu.raw.butsnum = 0;
		}

but this one,

		if (clu.raw.butsnum) {
			short int	down		= qfalse;
			int			but	= 0, i;

			for (i = 0; i < clu.raw.butsnum; i++) {
				switch( clu.raw.buts[i]) {
					case	 RI_MOUSE_BUTTON_1_DOWN:		down = qtrue;	but = K_MOUSE1; break;
					case	 RI_MOUSE_BUTTON_2_DOWN:		down = qtrue;	but = K_MOUSE2; break;
					case	 RI_MOUSE_BUTTON_3_DOWN:		down = qtrue;	but = K_MOUSE3; break;
					case	 RI_MOUSE_BUTTON_4_DOWN:		down = qtrue;	but = K_MOUSE4; break;
					case	 RI_MOUSE_BUTTON_5_DOWN:		down = qtrue;	but = K_MOUSE5; break;
					case	 RI_MOUSE_BUTTON_1_UP:		down = qfalse;	but = K_MOUSE1; break;
					case	 RI_MOUSE_BUTTON_2_UP:		down = qfalse;	but = K_MOUSE2; break;
					case	 RI_MOUSE_BUTTON_3_UP:		down = qfalse;	but = K_MOUSE3; break;
					case	 RI_MOUSE_BUTTON_4_UP:		down = qfalse;	but = K_MOUSE4; break;
					case	 RI_MOUSE_BUTTON_5_UP:		down = qfalse;	but = K_MOUSE5; break;
				}
				Com_QueueEvent( 0, SE_KEY, but, down, 0, NULL );
			}
		}
		clu.raw.butsnum = 0;

..sometimes "loses it" and if some of the "mouse buttons" (in that code) aren't pressed if they are hit too fast.

Anyway, the relevance of the code itself I guess is little.

Why do those pieces of code don't do exactly the same thing?

[Elysia]

Note how they are all if statements. So it checks "all" states, while the case only checks ONE state.
If RI_MOUSE_BUTTON_2_DOWN and RI_MOUSE_BUTTON_4_DOWN both are true, then the case will only execute the code for RI_MOUSE_BUTTON_2_DOWN and RI_MOUSE_BUTTON_4_DOWN, but the if statements will.

[User Name:]

If you just like using if statements, you could do one if with a crap load if else ifs(if that's even possible), but that would be ugly and I don't recommend it. I would be surprised if half the forum chastises me for even thinking of such a thing.

[DeadPlanet]

Because you're using bitwise ANDs in your first piece of code, I'll assume that clu.raw.buts[i] is a bitmask of one or more buttons. Switch cases only test for equality and so if more than one button is pressed then nothing at all will happen.

(I realise that this doesn't differ much from Elysia's post, but I think there's a typo somewhere in her last sentence which makes it confusing)