CODEWITHSUNDEEP
javaarraysboolean
EnkeiRC5
EnkeiRC5

Reputation: 139

I'd like to set all the values in a boolean array to false without re-initializing it

    public boolean used[] = new boolean[26];

Here is what I have, and it's working great. I know they are all going to be set as false by default. But, as my application is used for a while, some of those are changed to "true". (Which is fine, since that's what my code is supposed to do).

I'm trying to create a "reset" button, which will simulate a reset-like action. Where all variables are restored to what they were when the window was initially created (all drawings go away - just a fresh restart).

And I need all of those true booleans to go back to false in one fell swoop. Any ideas?

Upvotes: 9

Views: 28510

Answers (5)

Prerna Verma
Prerna Verma

Reputation: 1

    boolean a[]= new boolean[nums.length];

    Arrays.fill(a, false);

// this will help you fill array of boolean with false.

// remember to -> import java.util.Arrays;

Upvotes: 0

miks
miks

Reputation: 544

You can just recreate your array, it will be initialized by default to false.

That is when you implement the reset yo can do 

used[] = new boolean[26];

Upvotes: 2

user982733
user982733

Reputation:

Arrays.fill uses a rangecheck before filling your array. 

public static void fill(Object[] a, int fromIndex, int toIndex, Object val) {
        rangeCheck(a.length, fromIndex, toIndex);
        for (int i=fromIndex; i<toIndex; i++)
            a[i] = val;
    }

/**
     * Check that fromIndex and toIndex are in range, and throw an
     * appropriate exception if they aren't.
     */
    private static void rangeCheck(int arrayLen, int fromIndex, int toIndex) {
        if (fromIndex > toIndex)
            throw new IllegalArgumentException("fromIndex(" + fromIndex +
                       ") > toIndex(" + toIndex+")");
        if (fromIndex < 0)
            throw new ArrayIndexOutOfBoundsException(fromIndex);
        if (toIndex > arrayLen)
            throw new ArrayIndexOutOfBoundsException(toIndex);
    }

if you don't need rangeCheck, you can just use a forloop to fill up your boolean array.

for(int i = 0; i < used.length; ++i){
    used[i] = false;
}

Upvotes: 3

Chris Pitman
Chris Pitman

Reputation: 13104

Use Arrays.fill:

Arrays.fill(used, false);

Upvotes: 22

Ernest Friedman-Hill
Ernest Friedman-Hill

Reputation: 81674

Use java.util.Arrays.fill():

Arrays.fill(used, false);

Upvotes: 1

Related Questions