Page 149 - Computer science 868 Class 12
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The order in which the explicit conversion can be done is as follows:
byte short char int long float double
In the above order, the right-side data type is converted into the left-side data type in the explicit conversion.
Let us take an example for better understanding.
int a = 6, c;
double b = 4.5;
c = (int)(a+b);
System.out.println(c);
Output: 10
The mechanism of explicit conversion in the above example is as follows:
c = (int) (a + b ; Here, there are two different types of data
types. One int and another double. By default,
the added value will be converted into double.
double But with user’s intervention in the form of
int (int), the result will be converted into integer
int data type and stored in variable c.
Note: boolean data type is not compatible with any other primitive data type. So, it cannot be converted
into any other type or vice-versa neither by implicit nor explicit data type conversion. If tried to be
converted, it returns an error, e.g., “incompatible types: char cannot be converted to boolean”.
5.4 WRAPPER CLASS
A Wrapper class in Java is a type of class that is used to convert primitive data types into objects and objects to
primitive data types. It wraps around a variable of one data type and converts it into an object. Thus, a wrapper class
provides a way to use the primitive data types (short, double, boolean, etc.) as objects in Java.
Two primary uses of Wrapper Class are:
• Converts a String value/Object into its primitive type and vice-versa.
• Objects can store primitive values.
Wrapper classes are included in Java in java.lang library package. The java.lang package contains eight wrapper classes
that are listed below.
S. No. Primitive Data Type Wrapper Class
1. boolean Boolean
2. char Character
3. byte Byte
4. short Short
5. int Integer
6. long Long
7. float Float
8. double Double
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Primitive Values, Wrapper Classes, Types and Casting 147

