Every day I love python more and more. Today, I was writing some code like: for i in xrange(N): do_something() I had to do something N times. But each time didn’t depend on the value of i (index variable). I realized that I was creating a variable I never used (i), and I thought “There … Read more
This question already has answers here: Is there a concise way to iterate over a stream with indices in Java 8? (23 answers) Closed 8 years ago. Is there a way to build a forEach method in Java 8 that iterates with an index? Ideally I’d like something like this: params.forEach((idx, e) -> query.bind(idx, e)); … Read more
Many Python programmers are probably unaware that the syntax of while loops and for loops includes an optional else: clause: for val in iterable: do_something(val) else: clean_up() The body of the else clause is a good place for certain kinds of clean-up actions, and is executed on normal termination of the loop: I.e., exiting the … Read more
I would like to loop through a list checking each item against the one following it. Is there a way I can loop through all but the last item using for x in y? I would prefer to do it without using indexes if I can. Note freespace answered my actual question, which is why … Read more
What is the best way to guard against null in a for loop in Java? This seems ugly : if (someList != null) { for (Object object : someList) { // do whatever } } Or if (someList == null) { return; // Or throw ex } for (Object object : someList) { // do … Read more
What, if any, is the performance difference between the following two loops? for (Object o: objectArrayList) { o.DoSomething(); } and for (int i=0; i<objectArrayList.size(); i++) { objectArrayList.get(i).DoSomething(); } 16 Answers 16
This question already has answers here: How to zero pad a sequence of integers in bash so that all have the same width? (15 answers) Closed 6 years ago. I have a basic number for loop which increments the variable num by 1 over each iteration… for (( num=1; num<=5; num++ )) do echo $num … Read more
I would like to exit my for loop when a condition inside is met. How could I exit my for loop when the if condition has been met? I think some kind of exit at the end of my if statement, but don’t know how that would work. Dim i As Long For i = … Read more
I almost never see a for loop like this: for (int i = 0; 5 != i; ++i) {} Is there a technical reason to use > or < instead of != when incrementing by 1 in a for loop? Or this is more of a convention? 21 Answers 21
I try with a loop like that // ArrayList tourists for (Tourist t : tourists) { if (t != null) { t.setId(idForm); } } But it isn’t nice. Can anyone suggest me a better solution? Some useful benchmarks to make better decision: While loop, For loop and Iterator Performance Test 18 Answers 18