What is Integer class in java and how it works?

Java has a comprehensive collection of built-in Classes and Interfaces. Among them, one of the popularly used class is the Integer classes in Java, which is a part of the wrapper class for primitive type. In this blog, you will learn  all about integer classes in the following order:

• • What is an Integer class in Java?
  • Java.lang.Integer class Constructor
  • Java.lang.Integer class Methods
  • Java Integer Examples

Let’s begin.

What is an Integer class in Java?

An Integer class in Java wraps a value of the primitive type int in an object. An object of type Integer contains a single field, which is int type. The Java Integer class falls under the Java.lang.Number package. Here’s a complete hierarchy:

java.lang.Object
      java.lang.Number
           java.lang.Integer

Java Integer class contains various constructors and methods. Let’s directly look into them.

Java.lang.Integer class Constructor

Java.lang.Integer class Methods

You can know more about these methods here.
Now that you know the different methods used in  Integer class, it’s time we implement some of its major methods.

Java Integer Examples

In this section, I have implemented the first five methods used in the “integer class in Java”. Similarly, you can implement the rest of them. Do let me know if you face any difficulty. Refer the reference code below:

package Edureka;

import java.io.*; 
import java.util.*; 

public class javaIntegerExamples{    
	    public static void main(String args[])  
	    { 
	    		 int value = 161;
	    		 // Get the binary equivalent
	    		 System.out.println("Binary equivalent:"+Integer.toBinaryString(value));
	    		 System.out.println("Bit Count:"+Integer.bitCount(value));

	    		 //example for byteValue()
	    		 int Value1=123;
	    		 Integer a = new Integer(Value1);
	    			System.out.println("Byte Value is "+a.byteValue());
	    			
	    		//compare two integer values
	    			System.out.println(Integer.compare(20, 20));
	    			System.out.println(Integer.compare(20, 19));
	    			System.out.println(Integer.compare(20, 22));
	    			
	    		//compare two integers
	    			Integer value2 = new Integer(50);
	    			System.out.println(value2.compareTo(50)); 
	    			System.out.println(value2.compareTo(49));
	    			System.out.println(value2.compareTo(51));
	    			
	    		//decode the string
	    			System.out.println(Integer.decode("0124")); //base8
	    			System.out.println(Integer.decode("0x124")); //base16
	    		 }
	    		 
	    }

Output:

Binary equivalent:10100001
Bit Count:3
Byte Value is 123
0
1
-1
0
1
-1
84
292

This brings us to the end of this article where we have understood Integer Class in Java. Hope you guys are clear with this topic.

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