Storing Value In Long Type Variable
Mar 31, 2014How can I store a value in long type variable whose range is greater than int type variable ....
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Is Type Irrelevant As Long As Value Is Within Boundaries Of Type Of Switch Expression
Apr 30, 2014If you have final int i = 1;
short s = 1;
switch(s) {
case i: System.out.println(i);
}
it runs fine. Note that the switch expression is of type short (2 bytes) and the case constant is of type int (4 bytes).My question is: Is the type irrelevant as long as the value is within the boundaries of the type of the switch expression?I have the feeling that this is true since:
byte b = 127;
final int i = 127;
switch(b) {
case i: System.out.println(i);
}
This runs fine again, but if I change the literal assigned to i to 128, which is out of range for type byte, then the compiler complains.Is it true that in the first example the short variable and in the second example the byte variable (the switch expressions) are first implicitly converted to an int and then compared with the case constants?
Converting Long (primitive Type) To String?
Nov 2, 2014I 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).
View Replies View RelatedStoring Multiple Rows Of Table In Java Variable
Feb 3, 2014Can I store multiple rows of a table in a two dimensional string array in java.. The table has 3 columns and approximately 10,000 rows.. Some pointers for coding to achieve this...
View Replies View RelatedStoring Input From User As String Variable And Then Converting It To Double?
Jul 8, 2014I am trying to make a program that calculates the change due in dollars and cents. The user inputs both the amount due and the amount tendered. My program only works with whole numbers?
View Replies View RelatedLong Type Output File - Print Prime Numbers Between Given Range Of Numbers
Aug 22, 2014I tried to create file and write the output of my program in it in java when i use WriteLong then the file does not contain long value, how I create this file my program is to print prime numbers between 500000 to 10000000
public class primenumber {
public static void main(String[] args) {
long start = 5000000;
long end = 10000000;
System.out.println("List of prime numbers between " + start + " and " + end);
for (long i = start; i <= end; i++) {
if (isPrime(i)) {
System.out.println(i);
[Code] ....
Servlets :: Making Attributes From Textboxes And Storing Latest Passed Variable?
Mar 12, 2015I am trying to make the variables that will be taken in from a type='text' box in HTML in NetBeans available to the other servlets as well as store and display the latest value passed into these boxes on the servlet page when the submit button is clicked or display null if the box has not yet received a value. However, I do not understand how to do this and do not understand as to why my current output is always null?
i) Is ServletContext().getAttribute("name of my textbox") really the way to pass the attributes to all servlets?
ii) Is ServletContext() passed in the service request?
iii) How to store the latest value passed into the submit box?
Here is my code
index.html
<html>
<head>
<title>Lab One</title>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
</head>
<body>
First Name: <input type="text" name="firstName">
[code]....
Convert Primitive Long To Long?
May 28, 2014I have this code which suppose to sort files by their length and return a string[] of th file names:
import java.io.File;
import java.util.ArrayList;
public class SizeOrder extends SuperOrder {
public String[] sortArray(File[] pathList) {
File[] absoluteOrderFiles = this.absoluteSort(pathList);
ArrayList<File> sizeOrderList = new ArrayList<File>();
[code]...
Now, in the following line: absoluteOrderFiles[absoluteIndex].length() < sizeOrderList.get(sizeIndex).length()
I need to use the compareTo which only exists in Long object.
How do I convert primitive long to Long?
and is it possible to do it in a single line?
Variable Out Of Type PrintStream
Jul 27, 2014I am trying to understand Life time of a variable by writing a below program. But unable to compile it as it is throwing some error. Code snippet and error as follows,
// Understanding Lifetime of a variable.
class LifeTime {
public static void main(String args[]) {
int x;
for(x = 0; x <3 ; x++) {
int y = -1; // y is initialized each time block is entered
[Code] .....
Please refer to the print screen attached 'LifeTime.jpeg' to this thread to know more about error.
Unexpected Type - A Returned Variable Required
Apr 2, 2014I'm making a Hangman program for Java, here's my code:
import java.util.Scanner;
public class Hangman {
/**
* @param args the command line arguments
*/
public static void main(String[] args) {
String answerWord = WordList.getWord();
[Code] .....
The Compiler gives me this only error:
Hangman.java:39: error: unexpected type
displayWord.charAt(i)=userInput.charAt(0);
^
required: variable
found: value
I understand that charAt returns i as a value and not a variable. What do I use to return a variable as I intended?
Private Variable With Type Of Abstract Class
Oct 10, 2014I've got an abstract class
public abstract class AbstractClass
{
//stuff
}
And a few classes that inherit from it
public class Class1 extends AbstractClass
{
//stuff
}
public class Class2 extends AbstractClass
{
//stuff
}
within another class I have a private variable with the type of the Abstract class, and within one of the methods I assign an object to the the variable like this:
public class Test
{
private AbstractClass temp;
public testMethod(){
Class1 anObject = new Class1();
temp = anObject;
}
}
Is this legal? Will temp become a Class1 object?
How To Get Access To The Method With A Parameter Of Class Type Variable
Feb 19, 2014how to get an access to the method with a parameter of class type variable, lets say: public void insert(Record newRecord, int pos)?
View Replies View RelatedDefine Variable When User Has To Type Into Program So It Can Be Converted
Sep 23, 2014I don't understand how i'm supposed to define a variable when the user has to type it into the program so it can be converted. This program i'm working on is supposed to convert from meters to feet (meter = feet * 0.305) but the user has to type in the meters they want converted. how do i solve the problem that keeps coming up that says "variable meter symbol cant be found" ? I keep trying different lines to no avail
public class Lab2
{
public static void main(String[] args) {
double feet = meter * 0.305;
double meter = feet/0.305;
System.out.println("Enter in feet for conversion to meters");
meter = meter * 0.305;
[Code] .....
Void Is Invalid Type For Variable Action Performed
May 1, 2015I get an error in a program "void is an invalid type for the variable action performed"
Here is the code of my program.
import java.awt.EventQueue;
import javax.swing.JFrame;
import java.awt.Label;
import java.awt.BorderLayout;
import java.awt.Button;
import java.awt.TextArea;
[Code] .....
Display Month Using Enumerated Data Type From String Variable
Apr 1, 2014I have created an enumerated data type that represents months. In my program I have asked the user for the month. I hold the month entered by user into a string variable. From that string variable I'm trying to display the month using my enumerated data type. I know I can use if statements, but is there another simple way to do it?
import java.util.Scanner;
public class demo {
//Enum class called month that has constants in it representing months
enum month{january,february,march,april,may,june, july,august,september,
october,november, december};
[Code] ....
Getting Error While Creating A Method - Void Is Invalid Type For Variable
Jun 25, 2014I am new to Java and trying to learn it.I wrote the following program but while creating the method nav i am getting errors.
Error:- void is an invalid type for the variable nav
import org.openqa.selenium.*;
import org.openqa.selenium.firefox.FirefoxDriver;
import java.util.*;
public class YahooHomepage {
private static WebDriver driver;
[Code] .....
Swing/AWT/SWT :: Void Is Invalid Type For Variable Action-performed
May 1, 2015Here is part of my program that contains the code giving me problems.
import java.awt.EventQueue;
import javax.swing.JFrame;
import java.awt.Label;
import java.awt.BorderLayout;
import java.awt.Button;
import java.awt.TextArea;
import java.awt.Choice;
import javax.swing.JRadioButton;
[code]....
Object Reference Variable Unwilling To Be Reset To A Different Object Type
Nov 6, 2014I don't understand why the object reference variable 'a' cannot be recast from a thisA object reference to a thisB object reference.Is it the case that once a reference variable is linked to a particular object type then it cannot switch object types later on.I am facing the Java Associate Developer exam soon and I am just clearing up some issues in my head around object reference variable assignment,
class thisA {}
class thisB extends thisA { String testString = "test";}
public class CastQuestion2 {
public static void main(String[] args) {
thisA a = new thisA();
thisB b = new thisB();
[code]....
Unique ID / Not Too Long
Apr 15, 2014I am looking for a program to generate a unique alphanumerical identifier that is not too long; for example would start out with 6 digits like a licence plate or a postal code ex: AAA001 and use up all the possible combinations until 999ZZZ (just an example) and then when the possibilities are exhausted a 7th digit is added and so on. It matters not if they are sequential, the identifier just needs to be unique and not be too hard to remember (also i don't want to use ip adress or any personal identification). How I can accomplish this using java.
View Replies View RelatedGetting Int Type Cast To Lower Precision Char Type In Parasoft JTEST
Mar 11, 2014Below code I am using to typecast int to char.
char escapeValue = (char)0;
char cha = (char) 10;
escapeValue = (char)(escapeValue * cha); // Here am getting the above error.
I have 38 similar issues in my workspace.
How To Convert Input Array Of Type Strings To Class Type
Aug 14, 2014class Passenger{
String name;
int age;
char gender;
int weight;
public Passenger(){
[Code] ....
This is showing error.....error it gives isthat it cannot change from string type to passenger type......... How to do it??????
Addition Of Generic Type Parameter Causes Member Type Clash
Apr 22, 2014Got a problem with generics, which I'm still pretty new at. Here's a program that compiles fine:
import java.util.ArrayList;
import javax.swing.JComponent;
public class Experiments {
public static void main(String[] args) {
ListHolder holder = new ListHolder();
[Code] ....
It's useless, but it compiles. If I change Line 14, however, to add a generic type parameter to the ListHolder class, Line 10 no longer compiles:
import java.util.ArrayList;
import javax.swing.JComponent;
public class Experiments {
public static void main(String[] args) {
ListHolder holder = new ListHolder();
[Code] ....
I get this error:
Uncompilable source code - incompatible types: java.lang.Object cannot be converted to javax.swing.JComponent
at experiments.Experiments.main(Experiments.java:10)
Apparently, the introduction of the type parameter leaves the compiler thinking that aList is of type Object. I can cast it, like this:
JComponent c = ((ArrayList<JComponent>)holder.aList).iterator().next();
That makes the compiler happy, but why is it necessary? How does adding the (unused) type parameter to the ListHolder class end up making the compiler think the aList member of an instance of ListHolder is of type Object?
Random Long Variables In Array
Feb 2, 2014I have about 100,000 (N) random long variables in an array. I'd like to find if any two longs are equal; they're not expected to be. At this size, should I use the Hashtable or brute force it at a cost of N^2/2?
View Replies View RelatedMultiplying Long Integers 10+ Digits?
Nov 7, 2014Taking two input strings that are integers such as "1234" and "567" then multiplying as you would do by hand. Trying to get them saved in the n3 new string but something is going wrong. You also need to account for the zeroes that have to be added just like on paper.
String mulN(String n1, String n2) {
int p = 0, tmp = 0; int zeros = 0;
String n3= "";
String r = "";
for(int i = n2.length()-1; i >= 0; i--) {
[Code] .....
JSP :: JSTL And EL - Long Value Cast To String
Mar 27, 2015I'm trying to write a condition to jstl if tag,
<c:forEach var="ledg" items="user_ledgers">
<c:if test="${ledg.transactionID == param['trns']}">
<c:out value="${ledg.name}"/>
</c:if>
</c:forEach>
Ledg is an object of ledger class and transactionID is a field of type long.
I found this error while runtime.
javax.el.PropertyNotFoundException: Property 'transactionID' not found on type java.lang.String
I tried to convert transactioID value to String by several ways. But not working.
String concatenation
<c:if test="${(ledg.transactionID+’’) == param['trns']}">
Using custom tag
<c:set var="equals" scope="page">
<z:doTheyEquals v1="${ledg.transactionID}" v2="${param['trns']}"/>
</c:set>
It also expects String type.
Efficient GCD Calculation And Long For Loops
Jan 23, 2014My GCD testing:
Java Code:
public static long gcd(long a, long b) {
if(b == 0) {
return a;
} else {
return gcd(b, a % b);
}
} mh_sh_highlight_all('java');
Is there a more efficient way? Also, what can I do to speed this forloop up?
Java Code:
for(long i = 1; i < 750000; i++) { dothis; } mh_sh_highlight_all('java');