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];
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Subtract One User Inputted Integer From Another - Bad Operand Types
Mar 6, 2014I've been working on this problem for a while now and continue to get an error when I try to subtract one user inputted integer from another. It seems to compile fine for adding, dividing, and multiplying. Why it might be making that error and how to resolve it? (As an aside, I have no idea if I did the whole program right but am just trying to figure out why a declared int would come back with an error it's a string.)
import java.util.Scanner;
public class Calculate2
{
public static void main(String[] args)
{
int firstInt;
int secondInt;
int choice;
[Code] ....
Scan Postfix Expression From Left To Right Using Operand Stack
Apr 13, 2015package hw9;
import java.util.Scanner;
import java.util.Stack;
public class stack {
public static Integer evaluate(String expression) {
Scanner scanner = new Scanner(expression);
Stack <Integer> operands = new Stack<Integer>();
[Code] ....
When I input my expression which has spaces between characters e.g.:10 2 8 * + 3 -, it worked; when I put expression which may not add space between each char e.g.: 3 14+2*7/, the error showed:
Enter a postfix expression: 3 14+2*7/
Exception in thread "main" java.util.EmptyStackException
at java.util.Stack.peek(Stack.java:102)
at java.util.Stack.pop(Stack.java:84)
at hw9.stack.evaluate(stack.java:22)
at hw9.stack.main(stack.java:45)
Java Addition Of Time
Jun 28, 2014I work as a golf staff I would like to create application which would tell me the playing time and the time when players need to reach certain playing field/hole. my ideas is to make a program which would ask the user to input their starting time and than select the hole number, where the end result would be amount of actuall time.
I have been having hard time to figure out howe to properly structure the input conversion so it is recognized as a time (Exampke: 10:15). Do I need to use the calendar method in Java or ?
Addition Operation On Character Variables
Feb 8, 2015When addition operation is performed on the character variables ,then it specifies actually that the ASCII values are added because the character variable stores ASCII value of the character constant ,then why after the addition the result cannot be stored inside a character variable ,why it needs to be stored in an integer variable only ,when actually the character variable stores the ASCII value then why is it an error to store the added result in an character variable.
View Replies View Related2D Array Addition - Not A Statement Error
Dec 19, 2014I am new to java programming. I want to write a java program for 2D array addition. My code is:
Java Code:
class Matrixadd {
public static void main(String...s) {
int x[][]={
{1,2,3},
{4,5,6},
{7,8,9},
[Code] .....
I am getting a 'Not a statement' error at line 36.
Sparse Matrix Addition And Multiplication
Nov 4, 2014Code for sparse matrix addition and Multiplication...
View Replies View RelatedBuild A Servlet That Does Simple Addition And Subtraction?
Dec 10, 2014I am trying to build a servlet that does simple addition and subtraction then re displays the result on the same screen. I started the building the servlet I am just not sure I understand how to assign the value from a text area to a variable, so that I can complete the logic its still early stages, but its a simple app so it wont be a very long project(I hope lol). My question is how to assign the value that the user inputs to the text area to a variable that I can use?
My code and compile time errors:
C:UsersReignDesktopHTMLBank.java:89: cannot find symbol
symbol : variable Amount
location: class HTMLBank
if(Amount.equals("")||Amount.equals(null))//||Amount.equals(<0))
[Code].....
Add All Even Numbers Between 2 And User Input Number Which Is Included In Addition?
Apr 17, 2014import java.util.*;
public class SumOfAllEvens {
public static void main (String[] args) {
Scanner s = new Scanner (System.in);
//for (int i=1; i<4; i++){
int usernumber;
[code]....
I'm supposed to use a for loop that runs until it reaches the number input by the user, but I'm not sure how to tell the program to add the user's number along with all of the even numbers in between the user input and 2.
How To Use File Input / Output In Addition To Exception Handling
Dec 2, 2014I am trying to learn how to use file input/output in addition to exception handling... The problem is my textbook wrote this chapter for a version of Java that hasn't come out yet, so everything I do "according to the textbook" doesn't work. any feedback on correcting these exception errors because I am not sure what is causing them or how to fix them.
I was able to have it display the name of the book in the Book.txt file, but when I added the second part if the file doesn't exist, that's when the errors came up and it wouldn't compile.
import java.io.*;
import java.util.*;
public class DisplayBook
{
public static void main(String[] args) {
try {
File book = new File("Book.txt");
FileInputStream in = new FileInputStream(book);
[Code]...
These are the compilation error messages I am receiving: (I have managed to get it down from 7 errors to just 4, but now I'm stuck)
DisplayBook.java:15: error: unreported exception IOException; must be caught or declared to be thrown
while ((letter = in.read()) != -1) //if file exists, displays book title
^
DisplayBook.java:24: error: unreported exception FileNotFoundException; must be caught or declared to be thrown
[Code] ....
4 errors
Create Random Addition Or Subtraction From 0-500 Depending On Grade Level
Jun 13, 2014I need creating a code that will create random addition or subtraction from 0-500 depending on their grade level. I know how to create a random for the math and subtraction. I just dont know how to get it to change depending on their grade level. Example I need it to ask their name, grade level, addition or subtraction then five addition or subtraction questions depending on what they chose.
View Replies View RelatedCompound 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)??
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?
View Replies View RelatedOperator 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');
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 ?