For loops and the death of whiles

[Admin]

Syntactically, a for loop has the following anatomy:

Code:

for([i]variable declaration[/i]; [i]condition[/i]; [i]some actions[/i])

Typically, it's something like this:

Code:

for(int i = 0; i < n; i++) {
    // stuff
}// which is the same as...

int i = 0;
while(i < n) {
    // stuff
    i++;
}


Please don't do crazy for loops like these:

Code:

for(int a, b, c = 0; a < 5 && b != 0; scanf("%d\n"), a++) {
}

[Elusive]

An interesting feature of for loops, other than looking cleaner (yes, please don't do that), is that variables declared in the loop statement will only last until the loop ends, they have a very small scope.

Code:


for (int i = 0; i <= 9001; i++);
{
    printf("%d", i); // Will work
}

printf("%d", i); // Will not work, i is undeclared here.


You can always do this if you need that variable later, for whatever reason.

Code:


int i = 0;
for (; i <= 9001; i++)