Autoboxing and Unboxing in Java – AutoboxingAutoboxing refers to the automatic conversion of a primitive type variable to its corresponding. Autoboxing in java was introduced in Java Autoboxing and unboxing is a convenient way to auto transform primitive data type to it’s corresponding java. Primitive variables in Java contain values (an integer, a double-precision floating point Auto Boxing also comes in handy when we are working with

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VishalZanzrukia So just for getting more functionality? Unboxing is opposite of Auto Boxing where we convert the wrapper class object back to its primitive type. Auto Boxing is used to convert primitive data types to their wrapper class objects.

These Wrapper class have predefined methods for preforming useful operations on primitive data types. Some context is required to autoboxinf understand the main reason behind this. Java design went for having one ArrayList. Here is a simple program to illustrate the size and range of each data type in Java. Let me make it less obvious to the eclipse in the below code. Autoboxing is the automatic conversion that the Java compiler makes between the primitive types and their corresponding object autoboxng classes.

Similarly, there are wrappers called Float for floatDouble for doubleCharacter for charByte for byteShort for shortLong for long primitive, and Boolean for the Boolean type.

Anything else or other than the preceding primitives are a non-primitive or composite type. So why do we need it and why do we use autoboxing autpboxing unboxing in Java?

A hands-on introduction to frameworks and containers. It is rarely used, perhaps, so that you cannot say—OOPs! These features actually wrap up the naked primitives in the name autooboxing class which otherwise are nothing but atomic units. The most common example is: Now, we have primitive types and their corresponding wrapper classes, fine!


Jsva clicking “Post Your Answer”, you acknowledge that you have read our updated terms of serviceprivacy policy and cookie policyand that your continued use of the website is subject to these policies. This is not just a philosophical need; it has a practical merit as well. This allows us to do what we call substitution: Check out the java docs here.

Autoboxing and Its Pitfalls

Thus, the compiler converts the previous code to the following at runtime:. Converting a primitive value an intfor example into an object of the corresponding wrapper class Integer is called autoboxing. In contrast to atomic or primitive data types, there are other data types that are non-primitive or composite. Let’s see down the line.

They are all composite types. You do not need to call a method such as intValue or doubleValue. It was solved in a hacky way by generating these sources from a common one. The capability of autoboxing and auto unboxing also be seen with expressions.

For example, the int value 10 and 20 is auto boxed into a reference type by the addNumbers method whereas the return value is actually a primitive type but again is converted before storing into the result reference type.

This idea simplified coding of several algorithms, removing the trouble of explicit boxing and unboxing of values. Email Required, but never shown. Lastly, autoboxing facilitates work with the Collections Framework. Note that composite types are nothing but a autohoxing of primitives.

Autoboxing and Unboxing in Java

Autoboxing is the automatic conversion that the Java compiler makes between the primitive types and their corresponding object wrapper classes. This idea can be exploited to the autoboxijg of the programmer in a way where the seemingly simple looking primitive types are geared up with additional features. Autoboxing and unboxing lets developers write cleaner code, making it easier to read. The autoboxing and unboxing automates this and hence makes the code easier to read and less painful for developers to write.


While running the below code, NullPointerException NPE can be thrown and it is not quite obvious from the code if you are not aware of autoboxing. This is done automatically by JVM so that we can use a the wrapper classes for certain operation and then convert them back to primitive types as primitives result int faster processing.

This compensation may impact how and where products appear on this site including, for example, the order in which they appear. Now the problem is the combination of the above realities: For example, converting an int to an Integer, a double to a Double, and so on. Here is the ugly code to avoid the exception. What is your company size? Now, observe that the number of conversion occurring at different points in the code. Because having to box primitives every time you want to use them as Object is inconvenient, there are cases where the language does this automatically – that’s called autoboxing.

Asynchronous and Event-Based Application Design. What is your job title? Here is the simplest example of autoboxing: Autoboxing What is Autoboxing?

Unexpected Behavior Confused Equals Autoboxing has brought with itself a lot of things that just are not obvious to a programmer. Autoboxing and Its Pitfalls.

Autoboxing and Unboxing in Java –

Most Popular Developer Stories. This would be a pain and was so until java 1. A widening primitive conversion does not lose information about the overall magnitude of a numeric value in the following cases, where the numeric value kn preserved exactly. Autoboxing has brought with itself a lot of things that just are not obvious to a programmer.