Ugly loop!

Hi every body! :o
Can you tell me what this strange code do?

for (int i = 0; i < 4; i++)
for (int i = 0; i < 2; i++)
for (int i = 0; i < 2; i++)
cout <<"Done!" <<endl;

It outputs "Done!" 16 times while iterating through some loops. It might be more clear if we indent:

Code:

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for (int i = 0; i < 4; i++)
  for (int i = 0; i < 2; i++)
      for (int i = 0; i < 2; i++)
        cout <<"Done!" <<endl;

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Done!
Done!
Done!
Done!
Done!
Done!
Done!
Done!
Done!
Done!
Done!
Done!
Done!
Done!
Done!
Done!

You'd get the same result from using one loop (though I imagine that the code you gave was originally intended as a demonstration of some loop principles):

Code:

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for (int i = 0; i < 16; i++)
        cout << "done" << endl;

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When posting code, be sure to use code tags. Place [ code ] at the beginning of your code, and [ / code ] at the end (without the spaces), and it will format the code so it looks better on the board. It puts it in a more appropriate font and preserves indentation.

As said...it's just a REALLY ugly and confusing way to print "done". You'd never need to nest for loops to do such a simple task.

...And it's usually a good idea to enclose your for, if, and else statements in braces {}.

Doing so will illustrate much more clearly where each statement is being applied to.

You usually see code like that on exams. Testing your ability to read syntax.

Quote:

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Originally Posted by ameber

Hi every body! :o
Can you tell me what this strange code do?

for (int i = 0; i < 4; i++)
for (int i = 0; i < 2; i++)
for (int i = 0; i < 2; i++)
cout <<"Done!" <<endl;

---

What the hell is wrong with people? Why don't you compile it and find out for yourself? :mad:

Quzah.

Quote:

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Originally Posted by quzah

What the hell is wrong with people? Why don't you compile it and find out for yourself? :mad:

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Probably because he's sitting in his computer lab taking an exam and was lookin for a quick answer, so he fired up IE while the instructor wasn't watching :D

Yeah.... a "What does this do?" isn't the brightest question to ask.

Anyway Ameber, you could say that the nested loops work from the "inside, out."(At least, that's a good way to visualize it) The inner-most loop executes until it's done, then the outer for loops will execute. This will continue until the outer-most loop's condition statement is false.

4*2*2 = 16 executions.

Compile it yourself next time. :mad: ;)

you are right! I'm sleeping instead of working hard!