What is the difference between a widening and narrowing conversion in Java?

Asked By: Belisaria Eiche | Last Updated: 13th February, 2020
Category: technology and computing programming languages
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A widening conversion changes a value to a data type that can allow for any possible value of the original data. This occurs if you convert from an integral type to Decimal , or from Char to String . A narrowing conversion changes a value to a data type that might not be able to hold some of the possible values.

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Accordingly, what is narrowing and widening in Java?

Widening is taking place when a small primitive type value is automatically accommodated in a bigger/wider primitive data type. Widening is taking place when a reference variable of a subclass is automatically accommodated in the reference variable of its superclass.

Additionally, what do you mean by type conversion? In computer science, type conversion or typecasting refers to changing an entity of one datatype into another. There are two types of conversion: implicit and explicit. Explicit type conversion can also be achieved with separately defined conversion routines such as an overloaded object constructor.

Additionally, what is narrowing in Java?

Narrowing refers to passing a higher size data type like int to a lower size data type like short. It may lead to data loss. Casting is required for narrowing conversion. Following program output will be 44.

What is automatic type conversion?

Also known as 'automatic type conversion'. Done by the compiler on its own, without any external trigger from the user. Generally takes place when in an expression more than one data type is present. All the data types of the variables are upgraded to the data type of the variable with largest data type.

34 Related Question Answers Found

Does constructor return any value?

No, constructor does not return any value. While declaring a constructor you will not have anything like return type. In general, Constructor is implicitly called at the time of instantiation. And it is not a method, its sole purpose is to initialize the instance variables.

What is widening conversion?

A widening conversion changes a value to a data type that can allow for any possible value of the original data. Widening conversions preserve the source value but can change its representation. This occurs if you convert from an integral type to Decimal , or from Char to String .

What is difference between implicit and explicit type casting?

The basic difference between implicit and explicit type casting is that implicit is taken care of by the compiler itself, while explicit is done by the programmer. In the above statement, the conversion of data from int to double is done implicitly, in other words programmer don't need to specify any type operators.

What is Polymorphism in Java?

Polymorphism in Java is a concept by which we can perform a single action in different ways. We can perform polymorphism in java by method overloading and method overriding. If you overload a static method in Java, it is the example of compile time polymorphism. Here, we will focus on runtime polymorphism in java.

Why do we need casting in Java?


Type casting in Java is to cast one type, a class or interface, into another type i.e. another class or interface. Type casting also comes with the risk of ClassCastException in Java, which is quite common with a method which accepts Object type and later types cast into more specific type.

What is Autoboxing in Java?

Autoboxing is the automatic conversion that the Java compiler makes between the primitive types and their corresponding object wrapper classes. For example, converting an int to an Integer, a double to a Double, and so on. If the conversion goes the other way, this is called unboxing.

What is data type in Java?

Data type specifies the size and type of values that can be stored in an identifier. The Java language is rich in its data types. Data types in Java are classified into two types: Primitive—which include Integer, Character, Boolean, and Floating Point. Non-primitive—which include Classes, Interfaces, and Arrays.

What is Upcasting in Java?

What are Upcasting and Downcasting in Java? Upcasting (Generalization or Widening) is casting to a parent type in simple words casting individual type to one common type is called upcasting while downcasting (specialization or narrowing) is casting to a child type or casting common type to individual type.

What is widening in Java?

Widening is replacing one primitive type with another primitive type for assignment-compatibility. Boxing is the automatic conversion of a primitive type (such as int or long) to a corresponding reference type (such as java. lang. Integer or java.

What is overflow in Java?


Java Overflow And Underflow. Overflow and underflow is a condition where you cross the limit of prescribed size for a data type. When overflow or underflow condition is reached, either the program will crash or the underlying implementation of the programming language will have its own way of handing things.

How do you cast in Java?

Variables
  1. Type Casting in Java. Type casting is used to convert an object or variable of one type into another.
  2. Syntax. dataType variableName = (dataType) variableToConvert;
  3. Notes. There are two casting directions: narrowing (larger to smaller type) and widening (smaller to larger type).
  4. Example.

What is primitive casting in Java?

Casting Primitive Types
Casting between primitive types enables you to convert the value of one type to another primitive type. This most commonly occurs with the numeric types. But one primitive type can never be used in a cast. Boolean values must be either true or false and cannot be used in a casting operation.

What is implicit and explicit?

There is no room for doubt because everything is clearly and directly communicated. This is what separates these two words. Something is implicit when it is implied but not directly stated. Something is explicit when it is directly stated and leaves no room for uncertainty.

What do u mean by variable?

In programming, a variable is a value that can change, depending on conditions or on information passed to the program. Typically, a program consists of instruction s that tell the computer what to do and data that the program uses when it is running.

What do you mean by implicit conversion?


Implicit type conversion means assigning value of a particular data type to a higher data type or to a similar data type. Example: An int data type can be assigned to a long , double , float , int or String data type variable.

What is keyword in C?

In C programming, a keyword is a word that is reserved by a program because the word has a special meaning. Keywords can be commands or parameters. Every programming language has a set of keywords that cannot be used as variable names.

Which type of conversion is not accepted?

Which type of conversion is NOT accepted? Explanation: Conversion of a float to pointer type is not allowed.