Integer types in java

Integer types:

• We have 4 integer types among eight available primitive types in java.
• We can represent size in bytes of memory.
• Integer data type values come under positive and negative.
• Data types allow you to select the type appropriate to the needs of the application..
• Java supports Primitive and Referenced data types.
• Primitive types are categorized as Integer, Floating, Character and Boolean.

Note: 1 byte = 8 bits = 2^8 = 256 à (-128 to +127)

Following are integer limits representation.

Wrapper classes:

• For every primitive type such as byte, short , float…, there is a corresponding wrapper class like Byte, Short, Float….
• Using wrapper classes we can perform data conversions like
  • Primitive à Object
  • Primitive à String
  • String à Object
  • ……
• Wrapper classes containing set of variables(static).
• Wrapper class variables are used to find the size and limits of each primitive type.

Printing byte limits and size:

class ByteInformation 
{
	public static void main(String[] args) 
	{
		System.out.println("byte minimum limit : " + Byte.MIN_VALUE);
		System.out.println("byte maximum limit : " + Byte.MAX_VALUE);
		System.out.println("byte size in bits : " + Byte.SIZE);
	}
}

• All variables are static.
• We need to access these variables their class names.
• These variables are constants(hence defined in capital letters)

class Sizes
{
	public static void main(String[] args) 
	{
		System.out.println("byte : " + Byte.SIZE/8 + " bytes");
		System.out.println("short : " + Short.SIZE/8 + " bytes");
		System.out.println("int : " + Integer.SIZE/8 + " bytes");
		System.out.println("long : " + Long.SIZE/8 + " bytes");
	}
}

Note: All wrapper classes providing the same set of fields(variables) to find the size and limits.

class LongInformation 
{
	public static void main(String[] args) 
	{
		System.out.println("long minimum limit : " + Long.MIN_VALUE);
		System.out.println("long maximum limit : " + Long.MAX_VALUE);
		System.out.println("long size in bits : " + Long.SIZE);
	}
}

Note: We select the data type depends on the value. We cannot store any value beyond its limit.

class Datatypes 
{
	public static void main(String[] args) 
	{
		byte b1 = 100;
		System.out.println(b1);

		byte b2 = 130;  // Error : out of range
		System.out.println(b2);
	}
}

We need to select the type depends on value range:

class Datatypes 
{
	public static void main(String[] args) 
	{
		byte b1 = 100;
		System.out.println(b1);

		short s1 = 130; 
		System.out.println(s1);

		long l1 = 50000;
		System.out.println(l1);
	}
}