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loopsconceptualconcept

Syntax/concept of a non-iterated loop?

I'm trying to iterate through a loop (any programming language, really, but for this exercise I happen to be using c#) and I was just wondering... what happens when you try to use a loop that doesn't iterate at all (i.e. ...."null"?)

For example:

int x = choose(0,1,2); 
for(int i=0;i<x;i++) {
    //some stuff
}

Like, what would happen if x gets chosen to be 0? Does it just become a useless for loop on that case? Will my program crash? Is that bad programming practice? etc. etc.

I'm mainly asking because I'm trying to format a concatenated string but only if some array has enough elements. thanks

Solution

  • Well simply put, nothing will happen. A for loop is like an if statement where it checks the condition and repeats while that condition is true. 

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

    This is saying:

    1. Initialize i to 0
    2. Check if i is less than the value of x
    3. Increment i at the end of the loop

    If x is 0, then the loop will simply not run; it becomes useless.