Guava - Booleans Class

Booleans is a utility class for primitive type Boolean.

Class Declaration

Following is the declaration for com.google.common.primitives.Booleans class −

@GwtCompatible(emulated = true)
   public final class Booleans
      extends Object

Class Methods

Sr.No	Method & Description
1	static List<Boolean> asList(boolean... backingArray) Returns a fixed-size list backed by the specified array, similar to Arrays.asList(Object[]).
2	static int compare(boolean a, boolean b) Compares the two specified boolean values in the standard way (false is considered less than true).
3	static boolean[] concat(boolean[]... arrays) Returns the values from each provided array combined into a single array.
4	static boolean contains(boolean[] array, boolean target) Returns true if target is present as an element anywhere in array.
5	static int countTrue(boolean... values) Returns the number of values that are true.
6	static boolean[] ensureCapacity(boolean[] array, int minLength, int padding) Returns an array containing the same values as array, but guaranteed to be of a specified minimum length.
7	static int hashCode(boolean value) Returns a hash code for value; equal to the result of invoking ((Boolean) value).hashCode().
8	static int indexOf(boolean[] array, boolean target) Returns the index of the first appearance of the value target in array.
9	static int indexOf(boolean[] array, boolean[] target) Returns the start position of the first occurrence of the specified target within array, or -1 if there is no such occurrence.
10	static String join(String separator, boolean... array) Returns a string containing the supplied boolean values separated by separator.
11	static int lastIndexOf(boolean[] array, boolean target) Returns the index of the last appearance of the value target in array.
12	static Comparator<boolean[]> lexicographicalComparator() Returns a comparator that compares two boolean arrays lexicographically.
13	static boolean[] toArray(Collection<Boolean> collection) Copies a collection of Boolean instances into a new array of primitive boolean values.

Methods Inherited

This class inherits methods from the following class −

• java.lang.Object

Example - Converting Array of Booleans to List and vice versa

GuavaTester.java

package com.tutorialspoint;

import java.util.List;
import com.google.common.primitives.Booleans;

public class GuavaTester {
   public static void main(String args[]) {
      GuavaTester tester = new GuavaTester();
      tester.testBooleans();
   }

   private void testBooleans() {
      boolean[] booleanArray = {true,true,false,true,true,false,false};

      //convert array of primitives to array of objects
      List<Boolean> objectArray = Booleans.asList(booleanArray);
      System.out.println(objectArray.toString());

      //convert array of objects to array of primitives
      booleanArray = Booleans.toArray(objectArray);
      System.out.print("[ ");

      for(int i = 0; i< booleanArray.length ; i++) {
         System.out.print(booleanArray[i] + " ");
      }

      System.out.println("]"); 
   }
}

Verify the Result

Run the GuavaTester and verify the output −

[true, true, false, true, true, false, false]
[ true true false true true false false ]

Example - Checking Presence of Element in Arrays of Booleans

GuavaTester.java

package com.tutorialspoint;

import com.google.common.primitives.Booleans;

public class GuavaTester {
   public static void main(String args[]) {
      GuavaTester tester = new GuavaTester();
      tester.testBooleans();
   }

   private void testBooleans() {
      boolean[] booleanArray = {true,true,false,true,true,false,false};

      //check if element is present in the list of primitives or not
      System.out.println("true is in list? " + Booleans.contains(booleanArray, true));

      //return the first index of element
      System.out.println("true position in list " + Booleans.indexOf(booleanArray, true));

      //Returns the count of true values
      System.out.println("true occured: " + Booleans.countTrue(booleanArray));

   }
}

Verify the Result

Run the GuavaTester and verify the output −

true is in list? true
true position in list 0
true occured: 4

Example - Comparing boolean values

GuavaTester.java

package com.tutorialspoint;

import com.google.common.primitives.Booleans;

public class GuavaTester {
   public static void main(String args[]) {
      GuavaTester tester = new GuavaTester();
      tester.testBooleans();
   }

   private void testBooleans() {
      //Returns the comparisons
      System.out.println("false Vs true: " + Booleans.compare(false, true));
      System.out.println("false Vs false: " + Booleans.compare(false, false));
      System.out.println("true Vs false: " + Booleans.compare(true, false));
      System.out.println("true Vs true: " + Booleans.compare(true, true));
   }
}

Verify the Result

Run the GuavaTester and verify the output −

false Vs true: -1
false Vs false: 0
true Vs false: 1
true Vs true: 0