I can understand result 3 is because of an upcast from short to int, since FunWithOverloading will not have a overloaded method with short now. However, what is happening with result 4? Shouldn't it call methodA of the subclass with the argument type short? If its because I have declared the reference variable, derived, of the type FunWithOverloading, then how come the first result correctly picks the overloaded method of the sub class?
class FunWithOverloading{
void methodA(int x){System.out.println("Integer method " + x);}
void methodA(short x){System.out.println("Short method " + x);} //line 3
} class OverloadedSubClass extends FunWithOverloading{
void methodA(short x){System.out.println("Sub class short method " + x);}
public class AutoBoxingExample { public void add(Integer intVal){ System.out.println("Wrapper"); } public void add(int value){ System.out.println("Primitive"); } public static void main(String[] args) { AutoBoxingExample auto = new AutoBoxingExample(); auto.add(12); } }
The output is "Wrapper". What would be the reason behind it?
I have an int array that has information read from a file. Now i want to display this int on a jtable but ofcourse i cant display primitive data types.. and also you cannot cast an int[] to an Object[], so I am stuck...
Trying to find a way to use primitive data types to overload sound()method. I can't seem to warp my head around using an int or a double to overload the method. And if I did, how do you call them in the main afterwards?
I get an error when I try to divide 500 miles by 25.5 gallons
Exception in thread "main" java.lang.NumberFormatException: For input string: "25.5" at java.lang.NumberFormatException.forInputString(Num berFormatException.java:65) at java.lang.Integer.parseInt(Integer.java:580) at java.lang.Integer.parseInt(Integer.java:615) at Mileage.main(Mileage.java:42) Java Result: 1
I am going through Thinking in Java, 4th Ed and I came across the section that talks about overloading variable arguments. I tried out a piece of code from the book. (Method and class names not exactly the same).
public class Varargs { public static void m1(Character... args) { System.out.println("Character");
[code]....
In the above code, the compiler throws an 'Ambiguous for the type varargs' error. The error goes away if the first method is changed to:
public static void m1(char c, Character... args)
why there is ambiguity in the first piece of code and not the second.
The class Overloading below asks for two names and prints three different greetings. Your task is to write the class methods missing from the class declaration. Methods print the greetings as shown in the example print. The names and parameter types of the needed methods can be checked from the main method because all methods are called there. This exercise also does not require you to copy the source code below to the return field. The method declarations will suffice.
Example output
Type in the first name: John
Type in the second name: Doe
Java Code:
import java.util.Scanner; public class Overloading { public static void main(String[] args) { String firstName, secondName; Scanner reader = new Scanner(System.in);
The class Overloading below asks for two names and prints three different greetings. Your task is to write the class methods missing from the class declaration. Methods print the greetings as shown in the example print.
Hint:The names and parameter types of the needed methods can be checked from the main method because all methods are called there. This exercise also does not require you to copy the source code below to the return field.
The method declarations will suffice.
Example output Type in the first name: John Type in the second name: Doe
********** Hi! ********** Hi, John ********** Hi, John and Doe **********
import java.util.Scanner; public class Overloading { public static void main(String[] args) { String firstName, secondName;
I was told to create a class named Billing that includes three overloaded computeBill methods for a photobook store.
The first method takes the price of the book ordered, adds 8% tax and returns the total due. The second method takes the price of the book, and the quantity, adds tax and returns the total. The final method takes the price, quantity and a coupon discount, adds tax and returns the total.
All of this I have managed fairly well, although I keep getting a strange error at the end of my program that the constructor is undefined. The problem bits of code(the one throwing the errors) are under the comment //Enter values into each of the methods
Code:
package org.CIS406.lab2;
public class Billing { //Declarations double bookPrice; int quantityOrdered; double couponValue;
[Code] ....
My first thought was to create a constructor for each of the methods that I am using...
I have a case in which I want to sort two types of ArrayLists (using quicksort) and the method originally coded only accepts a String ArrayList. The problem is that now I want to sort an ArrayList of type int but couldn't . . . so I decided to overload the method. Since it looks very ugly to copy and paste the same chunk of code only to change the method signature I wondered if there is a better way to make this method more dynamic and be able to take in different types of ArrayLists.
My code:
private ArrayList<String> sort(ArrayList<String> ar, int lo, int hi){ if (lo < hi){ int splitPoint = partition(ar, lo, hi); sort(ar, lo, splitPoint); sort(ar, splitPoint +1, hi);
I have having some trouble on counting the primitive operations on the pseudocode given below:
Algorithm 4. MaximumArray(Arr) Input: A 1-D numerical array Arr of size n 1) Let CurrentMax = a0 2) For i = 1 to n-1 3)If ai > CurrentMax Then CurrentMax = ai 4) End For Output: CurrentMax, the largest value in Arr
As of now, I know that for Line 1 there are 2 operations (one set and one read). I don't know how to figure out the for loop and If statement (line 2 and line 3 too).
I am totally new to Java. What is the purpose of this method?
Flow of the int x=3; like where does the 3 go step by step?
Passing Primitive Data Type Arguments (from oracle java tutorials)
Primitive arguments, such as an int or a double, are passed into methods by value. This means that any changes to the values of the parameters exist only within the scope of the method. When the method returns, the parameters are gone and any changes to them are lost. Here is an example:
public class PassPrimitiveByValue { public static void main(String[] args) { int x = 3; // invoke passMethod() with // x as argument passMethod(x);
I have to use a long primitive type for the input of a credit card number and ID the credit card by using the first number of the input; however, the only way I know for that is to use charAt, which is used for a String. Is there a way to convert long to String, or am I missing a better solution? (There's no code because I'm still doing the pseudocode).
I am currently working on modules of a java program but am having issues with this module . it gives this error code"syntax error on token '?', invalid primitive type".
class MultipleReturn { int getInt() { int returnVal = 10; try { String[] students = {"Harry", "Paul"}; //System.out.println(students[5]); //if i remove comment
I have a code in which I am reading input from System.in and Destination is some where else
Here is my code
File file=new File("D:/output.txt"); OutputStream os=new java.io.FileOutputStream(file); Scanner scanner=new Scanner(System.in); System.out.println("Enter Data to write on File"); String text=scanner.nextLine(); int c=Integer.parseInt(text); int a; while((a=c.read())!=-1) os.write(a); System.out.println("File Written is Successful");
In the line while((a=c.read())!=-1)
a compile time error is shown "cannot invoke read on primitive data type int"
