" In terms of methods supported by the classes, the methods of StringBuffer and StringBuilder are identical. They only differ in whether the methods are synchronized or not. " - Oracle Certified Associate Java SE7 Programmer Study Guide
I'm using the JOptionPane to display and receive information to/from the user. In addition to this, I am using StringBuilder to receive inputs from the user and then manipulate (append) that input to display the desired output.
//Example
(JOptionPane): "Enter text" (user input): Java is cool! (program): *stringBuilder.append(" I love it!") JOptionPane.showMessageDialog( ); .....
Psuedo-like code. The problem is that showMessageDialog(null, string) and not showMessageDialog(string, string). I want to display the enter text: " Java is cool! I love it! " in the JOptionPane. How do I accomplish this, since showMessageDialog only accepts (null, string).
I have an array made that represents digits and I am trying to make a method so that if there are zeros in front of the first significant digit I want to trim them, I understand you can't re size arrays so I have created a new array, but my code doesn't seem to run correctly? Here is my code I can't figure out what is wrong I've tried everything: (I put stars around the error**)
package music; import java.util.Random; public class Music { private int length; // length of the array private int numOfDigits; // number of actual digits in the array int[] musicArray;
I got situation where i have postal code as 0009 in database and the use is entering 0009 but somehow in my java code it only reading 9 from the xml file
This is how i define getter and setter :
When I debug the code i get this :
passed postalcode 9
if a user entered 0009 I what it to remain 0009
Java Code:
public String Postalcode=""; public void setPostalcode(String Postalcode) { this.Postalcode = Postalcode; } public String getPostalcode() { return Postalcode; }
In Oracle SQL, when you do trim(column_name), if column_name is blank spaces only (say datatype is CHAR(8)), then "trim(column_name) is null" is true.
In JPQL, if you do "TRIM ( BOTH FROM p.column_name ) is null", does it evaluate to true just like in Oracle SQL?
The reason I'm asking, is my colleague wrote some code in JPQL like below:
... TRIM ( BOTH FROM CONCAT(p.column_name, '#@') ) = '#@'
He said he originally wanted to compare the TRIM result to empty String '', but the result is false, so he concat the column to some junk.
So if after the TRIM, the result is the same junk he added, then the column contains only blanks. I think this works but there could a simpler way to do it.
How can I write a method that takes a string with duplicates letters and returns the same string which does not contain duplicates. For example, if you pass it radar, it will return rad. Also i would like to know how can I Write a method that takes as parameters the secret word and the good guesses and returns a string that is the secretword but has dashes in the places where the player has not yet guessed that letter. For example, if the secret word is radar and the player has already guessed the good guesses letters r and d, the method will return r-d-r.
I am currently trying to make a calculator in Java. I want to use the String split method to tokenize the string of characters inputted. I thought I was using the String split method wrongly, because I had surrounded the characters I wanted to delimit with square brackets. However, when I removed the square brackets, the code threw an exception when I pressed the equal button. The exception was a PatternSyntaxException exception. Am I using the String split method wrongly? And why is the exception thrown? Here is my code:
import javax.swing.*;//import the packages needed for gui import java.awt.*; import java.awt.event.*; import java.util.Arrays; import java.util.List; import static java.lang.Math.*; public class CalculatorCopy { public static void main(String[] args) {
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'm having trouble with the last few lines of the code. It's supposed to take a replacement string entered by the user and print out the new string. For some reason it's now allowing me to enter a replacement string
import java.util.Scanner; public class Project02 { public static void main(String[] args) { Scanner keyboard = new Scanner(System.in); System.out.print("Enter a long string: "); String lString = keyboard.nextLine();
[Code] ....
Output:
Enter a long string: the quick brown fox jumped over the lazy dog Enter a substring: jumped Length of your string: 44 Length of your substring: 6 Starting position of your substring in string: 20 String before your substring: the quick brown fox String after your substring: over the lazy dog Enter a position between 0 and 43: 18 The character at position 18 is x
Enter a replacement string: Your new string is: the quick brown fox over the lazy dog <------ isn't taking user input
I have a method for a button so when a user inputs something it then will get the string value and check it against the string value within the properties file to see if it exists.
The properties file is called GitCommands.properties that contains -- > key = value <-- in it
I realised I have not used it correctly hence why I keep getting errors - I am lost on how to use it, I think perhaps that may be the issue here? I need to reference the file but I am doing it wrong? When I do use that piece of code I get null pointer exception too...
JButton btnSearch = new JButton("Search"); btnSearch.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { FindSelectedKey();
[code] .....
I understand I am missing my piece of code where it states "//determine whether the string is equal to the property file key string" I understand the logic fine but not actually coding it.
I am trying to split a string based on length(example length 5) of the string. But I am having a issues with this substring(start, end) method. I get all substring which are of length 5. But if the last substring is less than 5 then I am not getting that last substring. But I need the last substring even if it is less than 5.
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.
public class test { public static void main(String[] args) { Printhelloworld(); String[] verbs = {"go", "do", "some", "homework"}; printArrays(verbs);
I'm having trouble to compare two string from my LinkedList. I took me 2 days now trying figure out how to compare the current string to previous string in the linkedlist. Here is my code.
public int compareTo(LinkedListNode n){ //Compare two string String myHead = data.toLowerCase(); String comparableHead = data.toLowerCase();
How do I compare a String to each element of a string array?
For example:
int headscount = 0; if (coins[i].equals("heads")){ headscount++; System.out.println("b" + headscount); }
This doesn't give me the right value because the IDE says that equals() is an incompatible type. I also tried changing the "heads" to an variable, but the results remains the same.
So I'm creating a class which when given three inputs uses them as sides of a triangle and tells ther user what type of triangle it is, or if the input is invalid, tells them why it is invalid. I'm readin the input as a string and then trying to split it into a string array, from there checking to see if it has 3 elements.. in which the data is good at that point, and then converting them to ints and checking to see if they're negative ansd finally checking to see if they can work as sides of a triangle ie a+b >c, a+c >b , b+c >a.
I'm trying to split it into an array of strings but am getting an error, and can't seem to figure out why as this should be working from what I've read of the string.split method online.
import java.util.*; public class TriangleTest{ private int sideA; private int sideB; private int sideC; public static void main(String[] args){ TriangleTest triangle = new TriangleTest("3 4 5");
I have a string value returned from a background tool that will range from 0 to possibly terabytes as a full number. I want to format that number to use commas and to reduce the character count using an appropriate size modifier (KiB, MiB, GiB, etc). I've tried converting the string number to a Double value using Double.parseDouble() and then performing the math based on the size of the value with this code:
I have errors in the "if" and both "else if" ... The compiler says "cannot convert from String to boolean and int to String ...
instructions:
1. Add two private instance variables, String courseName and char grade to this class.
2. Add accessor and mutator methods for these instance variables.
3. Add a method register which receives an integer data type and returns String data type according to the argument passed to it ("Math" for 1, "English" for 2, "No course" for any other input)
What I have so far:
package assignment9; public class BannerUser { private int userId; public int getUserId() { return this.userId; } public void setUserId(int userId)
I have the the string value similar to the one which i have to split based on the delimited "," String SampleString=" 'ab,c', 'xyz', lm,n,o "
I know I can easily call split function which will eventually split the above string. But in my case the delimiter "," , is also a part of the string. If I call the function SampleString.split(',') I will get the output as listed below
ab c xyz lm n o but the expected output is abc xyz lmno
I'm having a hard time with this problem, this is what I have, but I can not use two integers, I have to use one integer and a string...
This is the question:
Write a method called printStrings that accepts a String and a number of repetitions as parameters and prints that String the given number of times. For example, the call:
printStrings("abc", 5);
will print the following output: abcabcabcabcabc
This is what I attempted:
public class printStringsproject { public static void printStrings(int abc, int number) { for (int i = 1; i <= number; i++) { System.out.print("abc"); } } public static void main(String[] args) { printStrings(1, 5); } }
