Java is a versatile and popular programming language with powerful features, and even more powerful types. The int and Integer types are two of the most important types for Java developers. By understanding the differences between them, you can create better code faster.
Understanding the Difference Between Int and Integer in Java
The int type is an integral data type in Java. It is an 8-bit signed value that stores integer values from -128 to 127. It is useful for operations involving calculation, but because it has no object wrapper, it is more difficult to work with than its object equivalent, the Integer.
The Integer type is a wrapper for the int type, providing a much richer array of features. It stores the same primitive data as int, but it also adds features such as methods for conversion, comparison, and manipulation of data. This makes it much more convenient and intuitive to work with.
The Benefits of Using Integer Over Int in Java
Because an Integer is a wrapper covering an int, using Integer over int gives you access to numerous highly useful methods that can manipulate and convert data. In addition, it has been found to be more performant in certain tasks due to being able to take advantage of certain optimizations.
The use of Integer also allows you to work with values that are outside the range of int. For example, if dealing with numbers that can vary from -2,147,483,648 to 2,147,483,647 (which is beyond the range of an int) then using Integer would be more appropriate.
Types of Integer and Int Variables in Java
When working with variables in Java, you can employ two different types: primitive, or reference. Both of these types can deposit ints or Integers into memory as necessary. In addition, both are declared in the same way.
Primitive types are standard variables that store primitive values (including numbers). The value is stored directly, with no other information attached to it. This makes it much faster than a reference, but also much less flexible.
Reference types also store primitive values as necessary, but they also store information about the value itself. These variables are slower than primitives, but they provide much more flexibility in terms of manipulating data.
How to Declare an Integer or Int Variable in Java
Declaring an int or Integer variable in Java is fairly straightforward. Both are declared in the same manner: simply give them a name, followed by the type.
int myInt;Integer myInteger;
Note: You may also initialize variables when you declare them. This is done by assigning a value to them like so:
int myInt=5;Integer myInteger=10;
Assigning Values to an Integer or Int Variable in Java
Once an int or Integer has been declared, you can assign it to any value within the accepted range. For ints, this is -128 to 127, and for Integers it is any value up to 2,147,483,647.
myInt = 100;myInteger = 200;
Working with Strings and Integers in Java
A String, by definition, is a list of characters that usually represent textual data. However, you can convert this into an Int or Integer by using the powers of Java.
To convert from String to Integer:
String ageStr = "25";// Parse the String into an Integer and store the value. Integer ageInt = Integer.parseInt(ageStr); System.out.println(ageInt); // Prints 25
To convert from Integer to String:
Integer ageInt = 25;// Convert the Integer into a String and store the result. String ageStr = ageInt.toString(); System.out.println(ageStr); // Prints "25"
Common Operations with Integers and Ints in Java
Ints, due to their nature, can have basic mathematical operations performed on them. Below is a list of some common operations.
// Addition int x = 5; int y = 6; int sum = x + y; // sum = 11 // Subtraction int x = 5; int y = 6; int diff = x - y; // diff = -1 // Multiplication int x = 5; int y = 6; int product = x * y; // product = 30 // Division int x = 6; int y = 2; int quotient = x / y; // quotient = 3 // Modulus int x = 5 int y = 3 ; int remainder = x % y ; // remainder = 2
Comparing and Contrasting Integers and Ints in Java
When comparing integers and ints in Java, there are a few main points which should be taken into consideration. Primarily, the use of an Integer provides many additional features over that of an int. This includes features such as object-oriented programming techniques (such as wrapper classes), greater flexibility, and better performance in some cases.
However, ints must be kept in mind because they provide a much leaner alternative which can, in certain cases, offer superior performance than Integers. This is especially true when dealing with number-intensive operations such as math, where every extra bit matters.
Best Practices for Working with Integers and Ints in Java
When using Integers and ints in Java, there are certain best practices that should be followed at all times. Primarily, always be aware of what sort of data you are dealing with prior to assigning values. Also try to use the most efficient method for your task (such as opting for primitives where appropriate). Finally, be sure to fully understand the range of values for ints and Integers (from -128 to 127 vs up to 2^31 – 1) before attempting any conversions or calculations.