CODEWITHSUNDEEP
javafor-loop
Kommander Kitten
Kommander Kitten

Reputation: 283

Skipping certain iterations of a for loop

I'm currently writing a for loop to go through a 2D with 38 elements. However, some of those elements are null and I want the for loop to simply skip over them (because in the puzzle I'm solving they have no moves associated with them). A quick search revealed that I can skip an iteration with a simple continue statement in an if statement at the beginning of the for loop. However, I want to skip multiple iterations, and the if statement I wrote isn't working:

for (int i = 0; i < triplets.length; i++) {
    if (i == 18 || 19 || 25 || 26 || 28 || 29 || 31 || 32) {
        continue;
    }

Is there an alternative to making 8 individual if statements or am I stuck with that?

Upvotes: 0

Views: 493

Answers (2)

Cootri
Cootri

Reputation: 3836

Is there an alternative to making 8 individual if statements or am I stuck with that?

you can create excluding List and execute your code when current triplet doesn't exist in it (code is more concise without continue calls). 

List<Integer> exclude = Arrays.asList(18, 19, 25, 26, 28, 29, 31, 32);
for (int i = 0; i < triplets.length; i++) {
    if (!exclude.contains(i)) {
        ....//your code
    }
}

If the exclude list is big then it is a good idea to replace ArrayList with HashSet, which has O(1) search complexity instead of O(N) (but consumes about 5.5 times more memory for each element)

Upvotes: 2

ninja.coder
ninja.coder

Reputation: 9648

You are not giving the condition properly. It should be something like this:

if (i == 18 || i == 19 || i == 25 || i == 26 || i == 28 || i == 29 || i == 31 || i == 32) {
    continue;
}

Alternatively, I would suggest you to do something like this instead:

  1. Create a HashSet and put the values to be compared in it.

  2. Check if HashSet contains i and if yes then continue the loop. 

    Set<Integer> set = new HashSet<>();
set.add(18);
set.add(19);
set.add(25);
set.add(26);
set.add(28);
set.add(29);
set.add(31);
set.add(32);

if(set.contains(i)) {
    continue;
}

Upvotes: 5

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