Ints Class in Java

The Ints class is a utility class for primitive type int. Let us see the class declaration −

@GwtCompatible
public final class Ints
extends Object

Example

Let us see an example of one of the methods to perform concatenation. The concat() function in Ints class is used to concatenate the arrays passed as parameter −

import com.google.common.primitives.Ints;
import java.util.*;
class Demo {
   public static void main(String[] args) {
      int[] myArr1 = { 100, 150, 230, 300, 400 };
      int[] myArr2 = { 450, 550, 700, 800, 1000 };
      System.out.println("Array 1 = ");
      for(int i=0; i < myArr1.length; i++) {
         System.out.println(myArr1[i]);
      }
      System.out.println("Array 2 = ");
      for(int i=0; i < myArr2.length; i++) {
         System.out.println(myArr2[i]);
      }
      int[] arr = Ints.concat(myArr1, myArr2);
      System.out.println("Concatenated arrays = "+Arrays.toString(arr));
   }
}

Output

Array 1 =
100
150
230
300
400
Array 2 =
450
550
700
800
1000
Concatenated arrays = [100, 150, 230, 300, 400, 450, 550, 700, 800, 1000]

Example

Let us see another example −

import java.util.List;
import com.google.common.primitives.Ints;
public class GuavaTester {
   public static void main(String args[]) {
      GuavaTester tester = new GuavaTester();
      tester.testInts();
   }
   private void testInts() {
      int[] intArray = {1,2,3,4,5,6,7,8,9};
      //convert array of primitives to array of objects
      List<Integer> objectArray = Ints.asList(intArray);
      System.out.println(objectArray.toString());
      //convert array of objects to array of primitives
      intArray = Ints.toArray(objectArray);
      System.out.print("[ ");
      for(int i = 0; i < intArray.length ; i++) {
         System.out.print(intArray[i] + " ");
      }
      System.out.println("]");
      //check if element is present in the list of primitives or not
      System.out.println("5 is in list? " + Ints.contains(intArray, 5));
      //Returns the minimum
      System.out.println("Min: " + Ints.min(intArray));
      //Returns the maximum
      System.out.println("Max: " + Ints.max(intArray));
      //get the byte array from an integer
      byte[] byteArray = Ints.toByteArray(20000);
      for(int i = 0; i < byteArray.length ; i++) {
         System.out.print(byteArray[i] + " ");
      }
   }
}

Output

[1, 2, 3, 4, 5, 6, 7, 8, 9]
[ 1 2 3 4 5 6 7 8 9 ]
5 is in list? true
Min: 1
Max: 9
0 0 78 32