I have doubts in string declaration. As I know we can declare string in two ways:
1. String a=new String("Hello");
2. String b="Hello";
What is exact difference between them? Another thing is when I check (a==b) it retuns me false, but when I check a.equals(b) it returns me with true. Why So?
My isEmpty method only returns false. Is something wrong? I printed the empty and not empty for testing purposes.
//determines if there are any items in the queue
public boolean isEmpty() {
if (front == -1 && rear == -1) {
System.out.println("empty");
return true;
} else {
System.out.println("not empty");
return false
}
}
I am using saveToken(request) and isTokenValid(request) to stop duplicate request. But while checking isTokenValid(request), it always returns false.
View Replies View RelatedWhy isn't heig ever equal to heightShipArray[count] no matter what letter I type in
String[] heightShipArray = {"A", "a", "B", "b", "C", "c", "D", "d", "E",
"e", "F", "f", "G", "g", "H", "h", "I", "i", "J", "j"};
boolean trueHeight = true; // checks if height is a letter between a-j/A-J
do {
Terminal.printLine("Input height with letters A to J");
[Code] ...
My Question is Suppose I am declaring an String array as
String[] a
or
String a[]
or
Comparable[] a
Will there be any performance or other advantage or disadvantage using these syntax?
i am trying to write a class method which will take in a string and returns a string which is the reversed version of that string. it compiles fine but when i try to run it it states Main method not found in class StringReverse,please define the main method as public static void main(String[]args). I am new to java and cannot figure out
import javax.swing.JOptionPane;
public class StringReverse {
public String reverseString(String str){
JOptionPane.showInputDialog(null,"Please enter word");
char c = str.charAt(str.length()-1);
if(str.length() == 1) return Character.toString(c);
return c + reverseString(str.substring(0,str.length()-1));}}
I am new to Java and would like to ask how to do this question specifically:
Code a Java method that accepts a String array and a String. The method should return true if the string can be found as an element of the array and false otherwise. Test your method by calling it from the main method which supplies its two parameters (no user input required). Use an array initialiser list to initialise the array you pass. Test thoroughly.
The following alert returns an added string instead of adding the var together to give me a total?
var tvHours = prompt('How many hours of Tv do you watch last week?');
var webHours = prompt('How many hours of internet surfing did you do last week?');
var gameHours = prompt('How many hours of video games did you play last week?');
alert(tvHours + webHours + gameHours);
Also can you store a var in an alert? e.g ( var time = alert(tvHours + webHours + gameHours); ???
I must write a method that accepts a string and returns an int. The method should sum the unicode values of each character, so the string "ABC" should return 198. Also the only string class methods I'm aloud to use are length, charAt, and substring. I just don't know how the get the Unicode value.
View Replies View RelatedI'm trying to get the jsessionid cookie value using the following line in my jsp. It always returns empty string. Is this correct behaviour?
response.encodeURL("")
I'm training myself with the EJB 3 technology. I would like to create a stateless bean that instead of returning a String, it returns an object. I tried in the same way I did with the first exercise, but I'm getting several errors.
View Replies View RelatedI'm trying to come up with a method that would validate each turn a player makes. For a turn to be valid, it has to only contain numbers from 0 to 3(inclusive) and at least one digit must not be 0. Here is what I`ve come up with so far. For example, with "303" as the number and "101" as the turn, the turn would be valid and my method should return true, but it does not.
public static boolean turnIsValid (String number, String turn ){
boolean rep=false;
int pos1=0;
char min='0';
char max='3';
while(number.length()==turn.length()&&pos1<turn.length()){
[Code] ....
I tried to make a program that takes a string str, and char a and checks how many times the char is used in the string.
Example: the string Welcome and the letter e, is 2 times. so the program should print 2.
It compiles but when I run it and enter the information, i cannot get the printing line out.
Heres my code:
import java.util.Scanner;
class program
{
public static void main(String[] args) {
Scanner user_input=new Scanner(System.in);
String str;
String b;
System.out.print("Please enter a word");
[Code] .....
Is it possible to check to see if a what a user has entered is a string or a other variable type, if I'm asking this the right way?
View Replies View RelatedI have an assignment and one of the prompts is to do a binary search on an array if and only if the array of Strings is sorted. The binary search part I think I have completed, but it is the sorted array check that is throwing everything off. If the array is already sorted, return true; else, return false.
// Check if the array is sorted
public static boolean isSorted(String[] arr) {
//for (int i = 0; i < arr.length-1; i++)
//{
//if (arr[i].compareTo(arr[i+1]) > 0)
//return false;
//}
String[] arrSorted = arr;
Arrays.sort(arrSorted);
[code]....
I have a number of objects stored in an ArrayList called inventory. Let's say I have two objects inside.
inventory.add(new Lamborghini(2011, "aventador", 411.3, false));
inventory.add(new Lamborghini(2012, "sesto elemento", 512.3, true));
I am making a function to search through the whole inventory to see if any of the Lamborghini object has a certain model name such as aventador, diablo, etc....
This is what I have but I figured there's a big mistake when I make it true / false; it's making it going through the list and what's return is the last one instead of saying there's such match in the whole list or not.
public boolean hasCarModel(String modelName){
boolean exist = false;
for (Lamborghini lambo : inventory){
String carModelName = lambo.getModelName();
if(carModelName.equalsIgnoreCase(modelName)){
[Code] ....
I figured if I add break; under exist = true; it'll work because as soon as it found one match then it'll turn to true and break out the loop but I don't think this is the best way to do it right?
I'm supposed to use stacks (implemented with an array) to check to see if a string is a palindrome. I've finished all my classes and methods, but I'm getting an ArrayIndexOutOfBoundsException when I try to run my demo program.Here are my classes:
public interface Stack {
// Creates an empty stack
public void initializeStack()
// Returns true if the stack is empty, returns false otherwise
public boolean isEmpty();
// The stack can never be full, so always return false
public boolean isFullStack();
[code]...
I tried to make a program that takes a string str, and char a and checks how many times the char is used in the string. Example: the string Welcome and the letter e, is 2 times. so the program should print 2. It compiles but when I run it and enter the information, i cannot get the printing line out.
Heres my code:
import java.util.Scanner;
class program
{
public static void main(String[] args) {
Scanner user_input=new Scanner(System.in);
String str;
String b;
System.out.print("Please enter a word");
str=user_input.next();
[Code] ....
I have to check a String input from the user in the form of firstName lastName (i.e. John Smith). I have to check for an exception called NonAlphabeticCharacterException that gets thrown if there is anything but a number in that string. This is what I have right now but should I create an array of char for the alphabet and then check the whole string for non alphabetic characters?
for(int i=0; i<name.length(); i++) {
if()){
throw new NonAlphabeticCharactersException("Non-alphabetic character found");
}
}
I started using Java a couple of days ago, If you haven't guessed I want to see if the user is typing a full name or not, but I'm actually not too concerned with any more complexity than I mentioned in the title. It's ok if an input like "GLba b" comes out positive.
View Replies View Relatedwrite the logic in the below given Java method.
Public static boolean updateNetMap(String filepath, String nodename){
// check the file pointed by filepath to have entry for nodename.
// if it is there, get the start line no and end line no
// Based on the line nos, need logic to remove the contents from the file.
}
Below is the sample node entry, which we need to identify and delete (here nodename is WAS_CD1):
WAS_CD1:
:conn.retry.stwait=00.00.00:
:conn.retry.stattempts=6:
:conn.retry.ltwait=00.00.00:
:conn.retry.ltattempts=6:
:tcp.max.time.to.wait=0:
[Code]...
Java Code:
ButtonGroup bg=new ButtonGroup();
JRadioButton choice1=new JRadioButton();
JRadioButton choice2=new JRadioButton();
JRadioButton choice3=new JRadioButton();
JRadioButton choice4=new JRadioButton();
bg.add(choice1);
bg.add(choice2);
bg.add(choice3);
bg.add(choice4); mh_sh_highlight_all('java');
here i coded out my radio button..i am confused how to get the selected radio button of string and match with another array of String..
Basically the requirements are to take a sentence (string of text) and check to see how many times specific words come up and then add to the counter depending on the word.
But I can not seem to get it to add the instances of the goodwords and badwords.
package Strings;
import java.io.*;
public class SentimentAnalyser {
private static String analyse(String text) {
int pw = 0;
int nw = 0;
String[] searchword = { "bad", "terrible", "good", "awesome" };
[Code] ....
I'm doing a problem where the area of a triangle is returned (if valid). However, I want to return a message (i.e. 'triangle is not valid) if the triangle is invalid.
I'm not sure how to go about to doing this as my method (called area) will only let me return doubles. Possible to return a string in an else within my area method?
public class MyTriangle {
public static void main(String[] args) {
//triangle is valid if the sum of any two sides is bigger than the third
System.out.println(isValid(3, 4, 5));
System.out.println(area(543, 4, 5));
[Code] ...
Netbeans tells me it's an illegal start of expression during the initialisation of the interactWithUser method.
public class InvertLetter {
/**
* @param args the command line arguments
*/
public static void main(String[] args) {
/**
* String mit den Kleinbuchstaben.
*/
final String lowercase = "abcdefghijklmnopqrstuvwxyz";
[Code] ....
Let's say within a class I create a method that takes care of creating a java swing layout with labels, buttons etc.. then attach an action listener (inner class) for each button to change a respective label text. All I would need is that the action listener method can access and modify the label as needed.
Have read about static, protected, private, getters and setters but honestly bit confused about which structure should be adopted as a best practice. Global static protected variables for the labels along with private inner classes implementing ActionListeners believe will do the trick and will be able to access the labels but not convinced this is good practice.