What is the most elegant way to check if all values in a boolean array are true?

Question

I have a boolean array in java:

boolean[] myArray = new boolean[10];

What\'s the most elegant way to check if all the values are true?

Answer 1

It depends how many times you're going to want to find this information, if more than once:

Set<Boolean> flags = new HashSet<Boolean>(myArray);
flags.contains(false);

Otherwise a short circuited loop:

for (i = 0; i < myArray.length; i++) {
  if (!myArray[i]) return false;
}
return true;

Answer 2

You can check all value items are true or false by compare your array with the other boolean array via Arrays.equal method like below example :

private boolean isCheckedAnswer(List<Answer> array) {
    boolean[] isSelectedChecks = new boolean[array.size()];
    for (int i = 0; i < array.size(); i++) {
        isSelectedChecks[i] = array.get(i).isChecked();
    }

    boolean[] isAllFalse = new boolean[array.size()];
    for (int i = 0; i < array.size(); i++) {
        isAllFalse[i] = false;
    }

    return !Arrays.equals(isSelectedChecks, isAllFalse);
}

Answer 3

Arrays.asList(myArray).contains(false)

Answer 4

In Java 8+, you can create an IntStream in the range of 0 to myArray.length and check that all values are true in the corresponding (primitive) array with something like,

return IntStream.range(0, myArray.length).allMatch(i -> myArray[i]);

Answer 5

This is probably not faster, and definitely not very readable. So, for the sake of colorful solutions...

int i = array.length()-1;
for(; i > -1 && array[i]; i--);
return i==-1

Answer 6

In Java 8, you could do:

boolean isAllTrue = Arrays.asList(myArray).stream().allMatch(val -> val == true);

Or even shorter:

boolean isAllTrue = Arrays.stream(myArray).allMatch(Boolean::valueOf);

Note: You need Boolean[] for this solution to work. Because you can't have a primitives List.