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Using Constructors

Every class must have at least one constructor. If there is no constructors for your class, the compiler will supply a default constructor(no-arg constructor). A constructor is used to construct an object. A constructor looks like a method and is sometimes called a constructor method. A constructor never returns a value A constructor always has the same name as the class. A constructor may have zero argument, in which case it is called a no-argument (or no-arg, for short) constructor. Constructor arguments can be used to initialize the fields in the object. The syntax for a constructor is as follows. constructorName (listOfArguments) {     [constructor body] } public class MainClass {   double radius;   // Class constructor   MainClass(double theRadius) {     radius = theRadius;   } }