After 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?
I am having an array of strings and i want to find out whether these strings contained in the array contain a similar character or not.For example i am having following strings in the array of string:
aadafbd
dsfgdfbvc
sdfgyub
fhjgbjhjd
my program should provide following result: 3 because i have 3 characters which are similar in all the strings of the array(f,b,d).
I can sort strings in a collection by uppercase and then lowercase though I was wondering if there is any way of doing it in reverse, sorting by lowercase then by uppercase.
View Replies View RelatedI 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)??
I know instanceof is an operator and println is a method. But what is the difference between the two? How are they different/same?
View Replies View Relatedwhy operator overloading is not supported in Java.
View Replies View RelatedI 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] .....
It looks like an upside down v , i cant find it on my keyboard. I assume its a keyboard combo.
View Replies View RelatedThis 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] ....
So 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');
I 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];
I 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?
Write a program to find maximum between three numbers using ternary operator.
View Replies View RelatedMy 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?
The 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 RelatedI just wanted to ask that while evaluating any expression,is the operator precedence fixed or it varies according to the compiler ,?
View Replies View RelatedAs 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{}
So 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 ?
class 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?
write a program using nested switch case to show the different shops in a shopping mall.
View Replies View Relatedwhy this switch code does not work for the 'Q'. Everything works fine for the other cases, i.e. 1,2,3, and 'q', but when I type in 'Q', I get the default case. Please note all the values have been defined in an earlier part of the code but for simplicity's sake I have removed them below
do {
switch (choix) {
//demande le nombre de patons a achete
case '1':
[Code].....
I am making a programme for a calculator to - Divide, multiply, add and subtract. I have the code written but when I am running it and trying to add it was for some subtracting ....
import javax.swing.JOptionPane;
public class calculator3 {
public static void main(String[] args){
String number1,number2,operatorstring;
double result=0,a,b;
[Code] ....
I'm trying to create a simple java math question quiz using random operators, but keep sinking myself into deeper despair. The numbers must range from 0-9 and given an operator: +,-,/,*,%. Can't create a new method or use Case statements. The code isn't finished but don't want to make it any worse.
package marco;
import java.util.Scanner;
import java.util.Random;
public class Project {
public static void main(String[] args) {
Scanner keyboard = new Scanner(System.in);
Random rand = new Random();
System.out.println("How many questions do you want?");
[code]...
can give me a sample program which solves with switch case statement with nested if inside?
View Replies View RelatedHow do i check INT range for switch case: ?
int grade = 68;
switch (grade) {
case 100:
System. out.println( "You got an A. Great job!" );
break;
case 80:
System. out.println( "You got a B. Good work!");
break;
[code]....
Part 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.