Long vs Int in Java

When working with numbers in Java, the programmer has two data types to choose from: long and int. While both data types deal with whole numbers, they have some differences that programmers should be aware of before deciding which one to use.

Integers: the int data type

Integers are whole numbers that do not have a decimal point. In Java, the int data type is used to represent integers. An int variable can hold any whole number between -2,147,483,648 and 2,147,483,647.

int thisIsAnInt = 42;
System.out.println(thisIsAnInt);

Long integers: the long data type

Long integers are also whole numbers, but they can hold much larger values than int variables. In Java, the long data type is used to represent long integers. A long variable can hold any whole number between -9,223,372,036,854,775,808 and 9,223,372,036,854,775,807.

long thisIsALong = 123456789012345L;
System.out.println(thisIsALong);

Note that when assigning a long value to a variable, you must append an "L" to the end of the number to indicate that it is a long integer.

When to use int vs long

Programmers should choose int when they know from the beginning that the value they are working with will always be within the range of the int data type. This is because int variables take up less space in memory than long variables. Therefore, using int can help optimize your program's performance.

However, programmers should choose long when they need to work with numbers that are larger than the range of the int data type. For example, when dealing with very large numbers or when working with timestamps that require millisecond precision.

Conclusion

The int and long data types in Java both deal with whole numbers, but have different ranges of values they can hold. Programmers should choose the appropriate data type based on the range of values they need to work with. Choosing the right data type can make your code more efficient and less prone to errors.