Which loop is faster in c

In general optimization is a mugs game and you should not do it until everything else is done if at all but in certain applications, video processing and no doubt rendering for a game project it can be beneficial. Almost all worthwhile optimizations are a tradeoff, for example use more memory to get more speed or take longer but use less memory. You need to decide what's important and what you're prepared to trade for it in terms of speed, memory, complexity and coding effort.

Posted Apr am Matthew Faithfull. Some things to consider: First, the speed of a loop usually depends on the code performed within much more than the type of loop.

Second, which loop to use depends on the way you wish to control the loop. You can rewrite any type of loop as another, but that won't change your requirements and efforts for fulfilling them! OTOH, if your loop gets reiterated until a value exceeds a certain limit, a while or do loop makes more sense than for. Third, you don't even know there will be a bottleneck. Maybe the code runs faster than the user can perceive, no matter how you program it? It is wasted time and effort to start optimizing before you even know there is a problem that requires it!

Fourth, tweaking the code just for making it run faster may be self-defeating: modern compilers are extraordinarily good at recognizing code patterns and optimizing them. But if you deliberately tweak you code, that may prevent the compiler from performing these optimizations!

TL;DR Don't try to optimize until you've written the code, noticed a performance problem, and pinpointed the cause of the bottleneck! Add your solution here. OK Paste as. Treat my content as plain text, not as HTML. Existing Members Sign in to your account. This email is in use. Do you need your password? Submit your solution! When answering a question please: Read the question carefully. Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.

If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome. In C , the For loop is slightly faster. For loop average about 2. The While loop averaged about 3.

As others have said, any compiler worth its salt will generate practically identical code. Using Pure Python In this case, the for loop is faster , but also more elegant compared to while. Please, have in mind that you can't apply list comprehensions in all cases when you need loops. Some more complex situations require the ordinary for or even while loops.

What you do inside the loop is slow in comparison to vectorized operations. I would expect a while loop to be slower than a for loop since it needs to test a condition before each iteration. A for loop is just syntactic sugar for a common pattern of while loop. Therefore, to answer your question, neither is faster than the other, because they're actually the same thing.

They even will optimize the same loop differently depending on what comes before and after the loop. How does a for loop start? The For Loop Statement 1 is executed one time before the execution of the code block. Statement 2 defines the condition for executing the code block. Statement 3 is executed every time after the code block has been executed. The while loop is the more general one because its loop condition is more flexible and can be more complicated than that of a for loop.

The condition of a for loop is always the same and implicit in the construction. A for loop stops if there are no more elements in the collection to treat.

Which loop is better for or while? The for loop has overhead that the while loop does not have. Thanks for visiting DZone today,. Edit Profile. Sign Out View Profile. Over 2 million developers have joined DZone. For Each vs. While in C. For vs. We check out how fast each of these loops can loop through an array and a list.

Which one do you think will prevail? Like 4. Join the DZone community and get the full member experience. Join For Free. Now; base. First, I'm going to implement a For loop on: a single integer. WriteLine i ; sw. Range 0, ToArray ; sw1. WriteLine array[i] ; sw1.