you can also refer this link Local variables in java?Local variables in java?To meet temporary requirements of the programmers some times..we have to create variables inside method or bock or constructor such type of variables are called as Local Variables.
----> Local variables also known as stack variables or automatic variables or temporary variables
----> Local variables will be stored inside Stack.
-----> The local variables will be created while executing the block
in which we declared it and destroyed once the block completed. Hence the scope of local variables is exactly same as the block in which we declared it.
package com.javatask.in;
class A{
public static void main(String args[]){
int i=0; // Local variable
Let's say I have a loop that loops through objects in an ArrayList then does stuff with them. Is it better for me to store the object in a temporary local variable and do stuff with it, or always use the ".get(arrayindex)" thing?
Basically this code is supposed to create an int array of 50 elements, then pull the elements listed in positions 1-6 to make a lottery draw.
Problem is it gets down to that last "For" statement and then says "duplicate local variable i." If I attempt to separate it from the previous for loop with curly braces, then it gets mad and says it doesn't know what "local variable i" even IS. So I tried changing it to "j" in the last statement and it couldn't recognise that either. I feel like I need to change the variable name in that second for loop but I'm not sure how to make it understand that the second variable is going to be outputting the values from the first variable.
public class Lottery { public static void main(String[] args) { // TODO Auto-generated method stub int []nums = new int [50]; for (int i = 1; i <50; i ++) {nums[i] = i;}
So like, in lua programming language you can do things like,
Array = {1, 2, 3, abc = 5, efg = {123, 456, 789, hij = {"tests","works!"}}, hij = true}
Array[1] = 5
Array[3] = true
Can you do atleast something like this in java or?
I would like to do this because if let's say I was making a game, I could define what tiles are passable and which are not and then their location or something, so like this:
//p (passable) stands for if possible to walk on //c stands for tile image t = ["grass.png","water.png","chest.png"] Tiles = [ [p = false, c = t[1], x = 3, y = -2 ], [p = true, c = t[0], x = 4, y = 3 ],
I am unable to understand the meaning of this sentence "final reference variables must be initialized before the constructor completes.",What is trying to imply?
I have An Issue With My Java Applet. Im Trying To Share My Variables With Another Class, But Its Not Working.
Class 1
package com.Tobysmith10.game.main; import java.applet.Applet; import java.awt.Graphics; public class Game extends Applet{ public void init(){ setSize(850,480); public void paint(Graphics g){ g.fillOval(x,y,20,20); } }
Class 2
package com.Tobysmith10.game.main; import java.applet.Applet; public class gameLoop extends Applet implements Runnable{ public int x, y; public void run(){ while(true){ x = 100; y = 100; } } }
So im sharing the x and y variables with the Class 1 , but I get yellow lines under it and when i run the program, it crashes, how do I get class 1 to recognize the variables from class 2 ?
okay so it says that java int short and byte variables are the same thing. They take whole numbers. But what is the point of byte and short to even exist if int covers it all? Is the short and byte just for fun?
I am reading input from a file that has following information:
line 1 = numbers of integers in array, line 2 = elements in array1, line 3 = elements in array2.
These lines constitute a test case. There are 1000 test cases in the input file.
So basically, I read the length of arrays, populate the arrays by reading from the file.
The code is below ( I have not included reading input code):
while(test_case<1000){ if (count == 1){ //count keeps track of lines in input file vec_length = Integer.parseInt (tokenizer.nextToken()); count++; continue; } if (count == 2){ //populates array1 vector1 = new int[vec_length]; for (int i = 0; i < vector1.length; i++) vector1[i] = Integer.parseInt (tokenizer.nextToken()); count++; continue; }
Array2 is populated using the same as above code. However when I use the following code:
for (int i=0; i<vec_length; i++) temp += vector1[i]*vector2[i];
I get " local variable vector1 and vector2 have not been initialized error". But both arrays have been initialized in the if{} block. Is it because initialization was local to if block?
As a studyproject I'm currently writing a class the allows me to get al fun dates (like when eastern is in a given year, what day a given date has, calculate the date of tomorrow).
While working on the following method:
public String getNextDate (int day, int month, int year) { String nextDate; int nextDay = getNextDay(day, month, year); int nextMonth = getNextMonth (day, month, year); int nextYear = getNextYear (day, month, year); return nextDate = "the day after " + month +"-" + day + "-" + year + " is " + nextMonth + "-" + nextDay + "-" + nextYear + "."; }
I get a notion in my lovely IDE (eclipse) reminding me I'm not using nextDate ("The value of the local variable nextDate is not used"). But I feel I really do use nextDay here. So either I'm making a coding(style) mistake giving me this notion or I should just ignore this notion.
Here, I have just tried out to take a value from the database and storing it into local variable then I want to have that value in the value attribute of <input> tag but somehow, I can't get it..
Here, below is my code..
<%@ page language="java" contentType="text/html; charset=ISO-8859-1" pageEncoding="ISO-8859-1"%> <%@ page import="java.sql.*" %> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "[URL]...."> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
I edited some lines from "[URL] ...." and saved it as html file; now if a friend want to do a search in Wikipedia for cats, the edited page should show up instead of original page.Is there a way to do this using java script.
How to check if a web page is synchronized on a local server in JSP ? I have tried to make database updation synchronized in jsp but how can i check it on local web server (tomcat) ? I have used Oracle database.
More Info:
Class.forName("oracle.jdbc.driver.OracleDriver"); Connection con=DriverManager.getConnection("jdbcracle:thin:@localhost:1521:xe","username","password"); balance=balance-1500; String query1= "update bank set bal=? where card_no='"+cnumber+"'"; PreparedStatement st1 = con.prepareStatement(query1); st1.setString(1,String.valueOf(balance)); int qresult1 = st1.executeUpdate();
This is some of the code in which I have not applied any synchronization. In simple words, I want to know how to test if synchronization part is really working or not ?
My main motive is... I am trying to make an admission form and I want a limited number of seats but I want after every registration process my database updates the seat numbers accordingly and show the right information about how many seats are left to the user. (though in the given code i am just changing the balance)
Like in this example <%! PreparedStatement pst = con.prepareStatement("query"); %> synchronization <% synchronized(pst) { pst.setXXX(...); pst.setXXX(...); pst.executeXXX(...); } %>
I have a question regarding best practice in using local variables as my method return variable. I have a method like this:
myReturnObject getMyObject(String input) { myReturnObject myObject = null; try { myObject = helperObject.someOtherMethod().getObject(input); //getObject has return type myReturnObject } catch (Exception e) { //log any problems } return myObject; }
And I'm wondering if I rewrite like this if I'll see some performance optimization benefit:
myReturnObject getMyObject(String input) { try { return helperObject.someOtherMethod().getObject(input); //getObject has return type myReturnObject } catch (Exception e) { //log any problems } return null; }
myObject can be quite large -- so I'm wondering if I can omit the myReturnObject local variable instance if it'll save some work from the garbage collector.
I would like to ask how i can create a bidirectional folder copy system with SFTP JSch is there any example. Like i see the code can only transfer file, I need to transfer a folder with many files from my pc to a server and the opposite.
I'm trying to create a server which sends the clients connected to it its local time. Looking at a few tutorials I've managed to connect the clients to the server, but can't send data to the clients. I've successfully done easier examples, without threading. I guess the problem might be im me not knowing what exceptions are for.
Client: When running the code "AAAAAAA" does execute but "BBBB" doesn't, so I guess the problem should be in fraseRecibida = entradaDesdeServidor.readLine();
import java.io.*; import java.net.*; import java.util.Scanner; public class Client { public static void main(String[] args) throws Exception{ String fraseRecibida;
[code]....
I don't understand the exceptions, maybe I should give them a look before continuing with sockets. Being frank I'm not really sure why the while(true) is there.
import java.io.*; import java.net.*; import java.util.Calendar; public class ServerThread extends Thread{ Socket socket; ServerThread(Socket socket){ this.socket = socket;
I've generated SOAP classes via wsimport from a local WSDL. All of the URLs in the WSDL point to the production services, but for testing I need to connect to a test location (different URL). There are dozens of examples on the web to set the endpoint, but it doesn't seem to be working for me - it's hitting the prod URL, not test.
PrepaidServices ps = new PrepaidServices(); ps.setHandlerResolver(new CustomHandlerResolver()); IPrepaidServices port = ps.getPrepaidServices(); BindingProvider bp = (BindingProvider) port; bp.getRequestContext().put(BindingProvider.ENDPOINT_ADDRESS_PROPERTY, TEST_URL); LOG.debug("New Port = " +
[Code]...
The debug correctly shows the TEST port being set correctly, but when executed, inside one of the handler resolvers, I have the following code:
