Java Long Class

Introduction

The Long class in Java is a wrapper for the primitive type long. It provides methods for converting and manipulating long values, handling arithmetic operations, and comparing longs.

Table of Contents

1. What is Long?
2. Creating Long Instances
3. Common Methods
4. Examples of Long
5. Conclusion

1. What is Long?

Long is a final class that wraps a long value in an object. It offers methods for converting between long and String, performing arithmetic operations, and comparing longs.

2. Creating Long Instances

You can create Long instances in several ways:

• Using the Long constructor: new Long(long value) or new Long(String value)
• Using the Long.valueOf(long value) or Long.valueOf(String value) methods

3. Common Methods

• longValue(): Returns the value of this Long as a primitive long.
• toString(): Returns a String representation of the long value.
• parseLong(String s): Parses a String to a primitive long.
• compareTo(Long anotherLong): Compares two Long objects numerically.
• compare(long x, long y): Compares two long values.
• MAX_VALUE: A constant holding the maximum value a long can have (2^63-1).
• MIN_VALUE: A constant holding the minimum value a long can have (-2^63).

4. Examples of Long

Example 1: Creating Long Instances

This example demonstrates how to create Long instances using constructors and valueOf methods.

public class LongInstanceExample { public static void main(String[] args) { Long l1 = new Long(10L); Long l2 = Long.valueOf(20L); Long l3 = Long.valueOf("30"); System.out.println("l1: " + l1); System.out.println("l2: " + l2); System.out.println("l3: " + l3); } } 

Output:

l1: 10 l2: 20 l3: 30 

Example 2: Parsing a String to long

This example shows how to parse a String to a primitive long using parseLong.

public class ParseLongExample { public static void main(String[] args) { long l1 = Long.parseLong("50"); long l2 = Long.parseLong("100"); System.out.println("l1: " + l1); System.out.println("l2: " + l2); } } 

Output:

l1: 50 l2: 100 

Example 3: Comparing Long Values

In this example, we demonstrate how to compare two Long values using compareTo and compare.

public class CompareLongExample { public static void main(String[] args) { Long l1 = Long.valueOf(10L); Long l2 = Long.valueOf(20L); int comparison = Long.compare(l1, l2); if (comparison < 0) { System.out.println("l1 is less than l2"); } else if (comparison > 0) { System.out.println("l1 is greater than l2"); } else { System.out.println("l1 is equal to l2"); } } } 

Output:

l1 is less than l2 

Example 4: Using MAX_VALUE and MIN_VALUE

This example demonstrates the use of MAX_VALUE and MIN_VALUE constants.

public class LongMinMaxExample { public static void main(String[] args) { System.out.println("Maximum Long Value: " + Long.MAX_VALUE); System.out.println("Minimum Long Value: " + Long.MIN_VALUE); } } 

Output:

Maximum Long Value: 9223372036854775807 Minimum Long Value: -9223372036854775808 

5. Conclusion

The Long class in Java is a useful wrapper for the primitive long type. It provides methods for converting, manipulating, and handling long values.