How would you instantiate a Resistor object with the parameterized constructor a

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A java constructor has the same name as the name of the class to which it belongs. Constructor’s syntax does not include a return type, since constructors never return a value. Constructors may include parameters of various types. When the constructor is invoked using the new operator, the types must match those that are specified in the constructor definition. Java provides a default constructor which takes no arguments and performs no special actions or initializations, when no explicit constructors are provided. The only action taken by the implicit default constructor is to call the superclass constructor using the super() call. Constructor arguments provide you with a way to provide parameters for the initialization of an object. Below is an example of a cube class containing 2 constructors. (one default and one parameterized constructor). public class Cube1 { int length; int breadth; int height; public int getVolume() { return (length * breadth * height); } Cube1() { length = 10; breadth = 10; height = 10; } Cube1(int l, int b, int h) { length = l; breadth = b; height = h; } public static void main(String[] args) { Cube1 cubeObj1, cubeObj2; cubeObj1 = new Cube1(); cubeObj2 = new Cube1(10, 20, 30); System.out.println("Volume of Cube1 is : " + cubeObj1.getVolume()); System.out.println("Volume of Cube1 is : " + cubeObj2.getVolume()); } } Download Cube1.java Note: If a class defines an explicit constructor, it no longer has a default constructor to set the state of the objects. If such a class requires a default constructor, its implementation must be provided. Any attempt to call the default constructor will be a compile time error if an explicit default constructor is not provided in such a case. Java Overloaded Constructors Like methods, constructors can also be overloaded. Since the constructors in a class all have the same name as the class, />their signatures are differentiated by their parameter lists. The above example shows that the Cube1 constructor is overloaded one being the default constructor and the other being a parameterized constructor. It is possible to use this() construct, to implement local chaining of constructors in a class. The this() call in a constructorinvokes the an other constructor with the corresponding parameter list within the same class. Calling the default constructor to create a Cube object results in the second and third parameterized constructors being called as well. Java requires that any this() call must occur as the first statement in a constructor. Below is an example of a cube class containing 3 constructors which demostrates the this() method in Constructors context public class Cube2 { int length; int breadth; int height; public int getVolume() { return (length * breadth * height); } Cube2() { this(10, 10); System.out.println("Finished with Default Constructor"); } Cube2(int l, int b) { this(l, b, 10); System.out.println("Finished with Parameterized Constructor having 2 params"); } Cube2(int l, int b, int h) { length = l; breadth = b; height = h; System.out.println("Finished with Parameterized Constructor having 3 params"); } public static void main(String[] args) { Cube2 cubeObj1, cubeObj2; cubeObj1 = new Cube2(); cubeObj2 = new Cube2(10, 20, 30); System.out.println("Volume of Cube1 is : " + cubeObj1.getVolume()); System.out.println("Volume of Cube2 is : " + cubeObj2.getVolume()); } } public class Cube2 { int length; int breadth; int height; public int getVolume() { return (length * breadth * height); } Cube2() { this(10, 10); System.out.println("Finished with Default Constructor"); } Cube2(int l, int b) { this(l, b, 10); System.out.println("Finished with Parameterized Constructor having 2 params"); } Cube2(int l, int b, int h) { length = l; breadth = b; height = h; System.out.println("Finished with Parameterized Constructor having 3 params"); } public static void main(String[] args) { Cube2 cubeObj1, cubeObj2; cubeObj1 = new Cube2(); cubeObj2 = new Cube2(10, 20, 30); System.out.println("Volume of Cube1 is : " + cubeObj1.getVolume()); System.out.println("Volume of Cube2 is : " + cubeObj2.getVolume()); } }

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