Difference Between Operator And Method
Jun 4, 2014I know instanceof is an operator and println is a method. But what is the difference between the two? How are they different/same?
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Compound Assignment Operator
Jan 8, 2014I just cant seem to understand the order of precedence here.
class Test{
public static void main(String[] args){
int k = 1;
k += (k = 4) * (k + 2);
System.out.println( k );
}
}
From what I have read compound operators have the lowest order of precedence... But the above piece of code makes the assignment k = 1 + (k = 4) * (k + 2) before evaluating the rest of the statement first.
It then evaluates (k = 4) and proceeds with the remained of the statement 1 + 4 * (4 + 6)....
I dont understand why the first k is assigned 1 but the remaining ks 4. Should they not all be 1 or 4 (I would have thought 4, since += has the lost order of precedence so is evaluated last)??
Operator In Case Of Strings
May 23, 2015After the executing the code below:-
class Test
{
public static void main(String [] args)
{
String s = new String("new") ;
String d = new String("new") ;
System.out.println((s==d)+ " "+s.equals(d)) ;
System.out.println(s==d + " "+ s.equals(d)) ;
}
}
OUTPUT:- false true
false
Why did the output change in the second print statement?
Why Operator Overloading Is Not Supported In Java
Oct 18, 2014why operator overloading is not supported in Java.
View Replies View RelatedUsing Values That Are Set For Cases In The Switch Operator
Mar 23, 2014I am new to Java and I am trying to use values that are set for cases in the switch operator.
The first menu ask for you to pick a product and each product has a price on it.
The second menu ask you to pick a state with each state having a decimal value on it.
The third is asking you to put the number of cases and each case is 12 items.
A key note to remember is that each part that a person is choosing is on a different instance!
Here is an example of what i am trying to do.
Menu 1: I picked case 1 that is Computer and it is worth 1000
Menu 2: I picked case 1 that is CT and it's tax is 7.5
Third choice: I picked case 1 and that has 12 items
I want the subtotal witch is: (1000 * 12)
Subtotal in this situation is: 120000
Next i need the total value which is based on what state they picked for the tax percent value picked from the state menu case: (12000 * 0.075 + 120000)
Total value is: 129000
I will post the code I have but based on the choices a person makes will determine the values and I need those values set in the cases to put in a math equation. The problem I am having is retrieving these numbers form the cases inside the menu options and they are on a different instance. So How can I do this in Java code?
Here is the code:
This is menu 1
Java Code:
import java.util.*; //scanners and more
class menu{
public void display_menu() {
System.out.println ("Please select your product"); //Gives user direction
System.out.println ( "1)
[Code] .....
How To Type Bitwise Operator Symbol
Jul 6, 2014It looks like an upside down v , i cant find it on my keyboard. I assume its a keyboard combo.
View Replies View RelatedProgram Ask For Operator And Two Numbers And Do Math
Feb 17, 2015This program is supposed to ask for the operator (+ or -) then ask you for two numbers and do the math. When I run it it comes up- Enter operator. When I say add or sub nothing happens. Here it is:
import java.util.Scanner;
public class Echo1{
public static void main(String args[]){
Scanner userInput = new Scanner(System.in);
System.out.println("Enter Operator");
String operator = userInput.next();
[Code] ....
HashMaps / ArrayLists - Diamond Operator?
Jul 8, 2014So I am learning HashMaps/Arraylists and I can't really understand the diamond operator or what it's for. Take the following code for example: Why could we not just do this without the diamond?
Java Code:
import java.util.HashMap;
class Untitled {
public static void main(String[] args) {
HashMap<String, String> map = new HashMap<String, String>();
map.put("California","Sacramento");
map.put("Oregon","Salem");
map.put("Washington","Olympia");
System.out.println(map);
}
} mh_sh_highlight_all('java');
Bad Operand Types For Addition Operator
Apr 25, 2015I would like to know that i am getting an error with the random. it is say bad operand types for binary operator ' +'
[/ Random generator = new Random(15) + 1];
And And Or Operator - Manipulate Bits In A Variable
Jun 1, 2014I am trying to understand what ivor is saying about the and, and or operators and the mask. If I understand it correctly the & operator prevents you from changing a bit that is one when a mask is involved and changes all others to 0 and the | operator forces a bit to 1 when the mask is 1.
My question is when would i need to actually use the & ,| operators ?when will i need to manipulate the bits in a variable?
Find Maximum Between Three Numbers Using Ternary Operator?
Aug 23, 2014Write a program to find maximum between three numbers using ternary operator.
View Replies View RelatedSource File - Arithmetic Operator Substitution
Nov 6, 2014My goals:
1) Have some source file be read in
2) Specify what arithmetic operators to swap (+, -, /, *)
2) If an arithmetic operator is read (like a + sign etc) then we swap it with its opposite (- for example)
3) Once the swap is complete, the rest of the file stays the same even if more operators are in the file...it is then output to a file (I am going with 1mutation.java)
4) This is where it gets tricky....it then picks up where it left off to finish reading the + operators (or whatever was specified) and repeats steps 2-3 (but the operator that is already swapped gets left as it was / skipped) and the output is saved as 2mutation.java.
The most I have been able to manage is having it changed 1 operator or all of them at once. I deleted a lot of my work to start fresh / master one operator for the time being. Here is what I have:
import java.io.BufferedInputStream;
import java.io.DataInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.PrintWriter;
public class OperatorSub {
[Code] ....
This is the data file I am using. (see attached) The file should be .java or .cpp but I stuck with .txt for now. How to tackle this? Am I on the right track?
IntelliSense - InstanceOf Operator Not Appearing Automatically
Jun 4, 2014The instanceof operator does not appear automatically(IntelliSense) when I press Ctrl+space. Instead some if condition involving instanceof is shown. What is special/unspecial about the instanceof operator not to appear in intellisense?
View Replies View RelatedEvaluation Of Expression - Operator Precedence Fixed Or Variable?
Feb 5, 2015I just wanted to ask that while evaluating any expression,is the operator precedence fixed or it varies according to the compiler ,?
View Replies View RelatedInstance Of Operator - No Output Generated Since If Condition Fails
Feb 2, 2014As per my knowledge, the instance of operator compiles only if the reference type compared to class type are in the same inheritance tree. According to that, below code should not compile but it compiles FINE!!.
Output:No output generated since the if condition fails
public class InstanceOfTest implements Inter{
public static void main(String arg[]){
Inter iot = new InstanceOfTest();
if(iot instanceof Someone) //here Inter(interface) and Someone(class) are not in the same inheritance tree.
System.out.println("iot is a Someone");
}
}
interface Inter{}
class Someone{}
Tester Class - Create Objects Of New Type And Then Use Dot Operator
Jun 12, 2014So I'm beginning to learn java with the book HeadFirst Java. The books says that all a tester class does is create objects of a new type and then use the dot operator...
I don't really understand what a tester class is and what it does ? and what is the Dot operator and how does it work ?
When Remove Increment Operator Program Shows Invalid Statement
Feb 19, 2015class Brain56
{
public static int[] get()
{
return null;
}
public static void main(String...a)
{
int k=1;
get()[k]++;
}
}
when i remove the increment operator(get()[k]) program shows invalid statement may i know the reason behind it?
Servlets :: Provide Interface To Operator To Manage Multiple Printers Of Smart Cards
May 9, 2014Part of my app is to provide an interface to an operator to manage multiple printers of smart cards.
A JSP page displays all printers and each printer has a print button.
I want the operator to press several buttons and each button pressed starts a thread.
Threads should run in parallel and pressing a button does not cancel the processing of the previous button.
Remove All Numbers From Queue And Push Onto Stack Until Operator Is Reached - Null Pointer Exception
Apr 26, 2015This method keeps throwing a NullPointerException. Not only that, but its not doing what I want it to do.
Heres the code:
/*
Remove all the numbers from the queue and push onto the stack until an operator is reached
*/
private static void processQueue() {
// Check what is at the front of the queue. If an operator is found or the queue is empty, exit method.
while(queue.front() != null || !queue.front().equals("*") || !queue.front().equals("/") || !queue.front().equals("%")
|| !queue.front().equals("+") || !queue.front().equals("-"))
{
stack.push(queue.removeFront()); // push the operand onto the stack
}
}
Here is the method that calls the processQueue() method
/*
Process the mathematical expression using a stack and a queue
*/
private static double processExpression() {
// insert all elements from the stack to the queue for processing
while(stack.top() != null) {
queue.insertBack(stack.pop());
[Code] .....
Difference Between Eclipse And JDK?
Feb 27, 2014I'm not sure if that's the right place to ask
But I am a bit confused:
I know that JDK means "Java Development Kit" , but isn't Eclipse the same thing? (so why it's called "IDE"?)
Or maybe Eclipse is a type of JDK?
Or actually JDK and Eclipse are 2 different things
JSF :: Difference Between EventHandler And ActionListener?
Feb 11, 2015What Is the difference between an ActionListener and an EventHandler ?
button.addActionListener(new ActionListener() {
button.setOnAction(new EventHandler<ActionEvent>() {
Difference Between Unused And Unread
Sep 19, 2014exact difference between
1. unread fields
2. unused fileds
in java
Difference Between Abstract And Inheritance
Dec 16, 2014I am new to java i dont understand the difference between the abstract and inheritance i mean we use the abstract class with extends with other class name ,even we do that same in the inheritance pls tell me main difference between abstract and inheritance...
View Replies View RelatedDifference Between Java And JavaScript?
Jul 11, 2014how to program in Javascript, I am wondering what are the advantages and disadvantages OR pros/cons of using JS versus say a language like Java?
View Replies View RelatedHow To Calculate Difference Between Two Dates
Oct 19, 2014I have been tasked with creating an invoice (school assignment). Part of the calculations is creating an interest depending on the amount of days between the current date entered, and invoice date entered (The program prompts the user to enter both the current and invoice dates by asking for the day, month and year).
We are also supposed to set the contructor to a default date of 1/1/1900.. but I don't know how or where to code that.
How to calculate the difference between the CurrentDate and Invoice. I have displayed the dates to the user as follows.
public void displayDate() {
System.out.println("
Today's Date: " + month + "/" + day + "/" + year);
}
public void displayInvDate() {
System.out.println("
Invoice Date: " + invMonth + "/" + invDay + "/" + invYear);
Difference Between LinkedList And ArrayList
Feb 19, 2014I have just begin to understand collections in Java. I read about the differences between LinkedList and ArrayList but have several doubts on it. I have mentioned them below
1) Why retrieving in ArrayList is faster then LinkedList?. Since both have the get method how does performance differ?.
2) How does re-sizing happens internally in ArrayList when a item is added or removed?. How slow this is compared to the pointer re-shuffling in LinkedList when a item is added or removed?.