I am working on an assignment covering exception handling and am stuck on part of the assignment. How can you test for array length = 0?
When I try something like: if (array.length == 0) on a null array, naturally I get a NullPointerException. I would try something like if (array != null) but both array length of 0 and null array are supposed to throw different expressions.
I have an assignment that wants me to write a Java function based on induction to determine how many numbers in an array have a value greater than, or equal to, 100.
I have started with:
Java Code:
int recurseHundred (int [] A, int n) {
//n is the number of elements in the array.
//Base case:
if (n == 1 && n >= 100) return A[0];
//Recurse
int num = recurseHundred(A, n-1);
if (n-1 >= 100) return A[n-1];
else return num;
} mh_sh_highlight_all('java');
I don't think this actually does the trick.
i know that int [][] x = new int[2][2] will generate a 2x2 array but I'm looking at a certification mock question and I see double [][] da = new double [3][]. What is the empty [] on the right hand side of the equal sign trying to tell me? Is there some default value?
View Replies View RelatedDivide an Array in two Parts in such a way so that sum will be equal while we add all the elements of array.
View Replies View RelatedI need comparing two array lists. For this program i am comparing 2 array lists. The list is integers entered by the user the second is random generated numbers. So far in my program i am able to compare the 2 arrays together and output if they are equal or not however i need the program to output even if atleast one if the integers match,
EXAMPLE list one: 1, 2 ,3 ,4, 5. LIST TWO: 1, 3, 3, 3, 3.
Since the first number matches i want it to out put there is one match, so on and so forth with if there are 3 or 4 matching integers. here is my code so far.
public static void main(String[] args)
{
final int NbrsEntered = 5; //Number of guessed numbers entered
final int LOTTOnbr = 5;
int[] numbers = new int[NbrsEntered];
int[] randomNum = new int[LOTTOnbr];
//int[] TestArrayOne = { 1, 2, 3, 4, 5 };
//int[] TestArrayTwo = { 1, 2, 3, 3, 5 };
boolean arraysEqual = true;
int index = 0;
[Code] ....
Given an array of scores, return true if each score is equal or greater than the one before. The array will be length 2 or more.
scoresIncreasing({1, 3, 4}) → true
scoresIncreasing({1, 3, 2}) → false
scoresIncreasing({1, 1, 4}) → true
Java Code:
public boolean scoresIncreasing(int[] scores)
{
for (int i = 0; i< scores.length-1; i++) {
if (scores[i] < scores[i+1] || scores[i] == scores [i+1]) {
return true;
} else {
return false;
}
}
return false;
}
Unsure what the problem is, it will always return True for some reason...
I tried the following and it gives me null pointer exception. I just want to verify if what is the actual value of a length of an array?
Object [] obj = null;
System.out.println("length:" + obj.length);
how you can do array.length, I have an array with [][][][], and what do I do to find the length of one section?
So let's say
Java Code: int array[][] = {
{5, 5, 5, 5},
{4, 4, 4, 4},
{3, 3, 3, 3}
} mh_sh_highlight_all('java');
How do I find out the length of the {5, 5, 5, 5} which is 4. Because there are 4 place-holders.Is there a way?
I was inquiring about selecting random numbers from a Fibonacci array, the original post for which is here: Exiting a 'for' Loop Early. I have managed to achieve this with the following code:
System.out.println("Random numbers from the Fibonacci array");
for(int i = 0; i < limit; i++) //Limit is an 'int' of 15 & is set as the length of the Fib. array. I'm calling it for the Random array, too!!
{
Random dice = new Random();
int randomIndex = dice.nextInt(array.length); //The Fib. array was simply called 'array'!!
if (array[randomIndex] < 100)
{
System.out.print(array[randomIndex]+ " ");
}
}
When the code prints I get a random set of numbers which occur in the Fibonacci sequence preceding it. However, the actual length of this Random array also changes each time, and never more than the limit of 15 specified in the 'for' loop. What I want to try and do is print the Random array with a specific length each time. I've tried changing the conditional statement of the 'for' loop in different ways to set the Random array's length, but had no luck.
I have an encoder that will shift the character of a string X places. Im trying to account for the possibility of the shift being larger than alphabet array length. I've come up with the following, but I still get an ArrayIndexOutOfBounds Error and it never gets past the if statement.
private String encryption(char charArrayElement) {
String [] alphabet = {"A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L",
"M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z"};
String str = String.valueOf(charArrayElement);
[Code] ....
In my programming class we need to create a large test array of Longs to iteratively sum/reverse the array and recursively sum/reverse the array.creating the array and where to go from there.
View Replies View RelatedI have a program that works, but I would like to know an easier way to record and print from a large array.
Here is what I have
package pa2;
import java.io.IOException;
public class PA2Delegate {
//long[] array = new long[100000];
int arraySize = 100000;
int iterations = 9999;
Long[] array;
[code].....
I'm making a program for school that reads a text file with answers to a personality test and prints the temperament to an output file. Problem is, it sets the temperament for the first person to INFJ and then prints INFJ for the rest of the people too. My code is below, and the input file 'personality.txt' goes like this:
Betty Boop
BABAAAABAAAAAAABAAAABBAAAAAABAAAABABAABAAABABABAABAAAAAABAAAAAABAAAAAA
Snoopy
AABBAABBBBBABABAAAAABABBAABBAAAABBBAAABAABAABABAAAABAABBBBAAABBAABABBB
Bugs Bunny
[Code] ....
This is my Code :
public static void main(String[] args) throws FileNotFoundException {
welcome();
Scanner input = new Scanner(new File("personality.txt"));
PrintStream out = new PrintStream(new File("output.txt"));
int[][] outcome = new int[4][2];
double[] percent = new double[4];
[Code] .....
I have been creating a Java program to track inventory using an array. I need to add a search function to it to take a term, input through a text field, and locate a matching instance within the array. How can I code a JButton to grab test input from a JTextField and search for it within the array then display the corresponding information? I also need to add buttons to add and delete items as well.
View Replies View RelatedI've seen this done in code:
For example:
Java Code: BufferedImageOp op = new ConvolveOp() mh_sh_highlight_all('java');
What does this mean? Is it creating an object of convolveOP for the BufferedImage class?
What does it mean when you set an object from one class equal to another?
How can I compare two date for less than or equal to ?
View Replies View RelatedI have an object that may contain several other objects (sub-object) and will compress those sub-objects.
My question is generally what is a good way to compare two objects, as described above, if they are equal (e.g. through equals() function)?
Intuitively there are two ways I can think of: 1. Compare each compressed bit
The disadvantage I think is it's not efficient if the object is very big. For instance, when it holds several gigabytes data, it may took too long for just comparing each bit.
2. Hash the sub-object before compressing it, and then compare all hashed values. This problem is I am not very sure if hashing is a good way to compare objects. And if collision may be the problem?
I have a JScrollPane with two coulmns. In the first column I have an image pane JTable, and in the second a list with names of sections. This second column I try to divide in two columns, one (the second column) to display the names of the sections (each row contains one name), and in the other column (the third) I want to show some values for every section in the row respectively. But, instead of displaying the desired values in the third column, I get the same names of the sections as in the second column. Here is a part of the code I have:
private Vector<Section>daten = new Vector<Section>(0); //These are the values for the first column in the Jscroll
private String[] header = {"Section","calcGYR"}; // These are the values for the second and third column (in this case the header for the both columns
public TrafficObserveModel(Vector<Section> daten) {
setData(daten);
[code]....
But I don't know how to modify the methods in order to render the desired integer values in the third column.
I read this tutorial about overriding equal and hashcode method. [URL] ....
I understand how to override equal method, by overriding it, We can custom our compare. I also understand How to override hashcode, To make custom hash.
But still I can not understand why we do it? why if equal method override, we must override hashcode method too?If we don't what is the problem?
To honor the above contract we should always override hashCode() method whenever we override equals() method. If not, what will happen? If we use hashtables in our application, it will not behave as expected. As the hashCode is used in determining the equality of values stored, it will not return the right corresponding value for a key.
Is it the right reason in order to override:
Because when we customize equal method so it focus on special variables,We must change the hash code too in order to match with it, so hashcode also focus on those special variable.
I'm suppose to create a program that will check if one statement is equal to another but it doesnt display the message if its equal to the inputted String
import java.util.Scanner;
public class sup {
public static void main (String args[]) {
Scanner in = new Scanner (System.in);
String one;
[code]...
thats just an example I was able to do it in C++ but it doesnt do what I want in Java
I would like to create a program that takes some files and modifies them in this way: The files should contain text formatted in this way:
##############
#various comments#
##############
something{
identifier=1234
anotherIdentifier=1235
anotherOne=12345
//and so on...
}//I need only this
#Comments are sometimes made this way
somethingAgain{
#comments that explains what's below them
I:dentifier:something, I, do, not, need
#see ^that
A:notherIdentifier:boolean
//and so on..
}
And I have to make so that the numbers contained in something{} in all the files don't match. I could ask to make so that the input file is only one, and it is formatted this way:
identifier=1234
anotherIdentifier=1235
anotherOne=12345
//and so on...
but I don't know how to do the rest of the program... That's what I've done (the names of the classes, package etc. are in Italian and there's some useless code that NetBeans prevents me from deleting):
package confronto;
import java.awt.Color;
import java.io.*;
import javax.swing.*;
public class confrontoTesti extends javax.swing.JFrame {
[Code] ....
Write java program using table that stores celsius and farenheit values that are equal to one another using a loop. use C 0-20 and convert to farenheit.
I have to use doubles for Celsius and Fahrenheit and in the formula. I get a runtime error with the following displayed:
I will display a table of temperatures in their Celsius and Farenheit equivalents.
celsiusfarenheit
import java.util.*;
import java.lang.*;
import java.io.*;
class TemperatureConversion {
public static void main (String[] args) throws java.lang.Exception {
double celsius;// Temperature in degrees Celsius minimum
double farenheit;// Temperature in degrees Fahrenheit
[Code] ....
I have written the code:
Java Code:
public static void main(String[]args)
{
Scanner input = new Scanner(System.in);
System.out.print("Type your text: ");
String text = input.nextLine();
int counter = text.length();
if(text.length()> 16)
[Code] ....
And input is: abcdefghijklm
output is:
Java Code:
a b c d
e f g h
i j k l
m x x x mh_sh_highlight_all('java');
So all i want is, if i type: abcdefghijklm
I want this output:
Java Code:
a e i m
b f j x
c g k x
d h l x mh_sh_highlight_all('java');
I want to know is there a limit for length of get url request? if if what is the max length.
View Replies View RelatedI have my code which will generate a random string using an ArrayList. However, I aso want to have it generate them in random lengths, not just using all the chars and numbers.
public static void main(String[] args) {
String[] CHARS = {"A","B","C","D","E","F","G",
"H","I","J","K","L","M","N",
"O","P","Q","R","S","T","U",
"V","W","X","Y","Z","1","2",
"3","4","5","6","7","8","9","0"};
List<String> pass = Arrays.asList(CHARS);
Collections.shuffle(pass);
for (String chars : pass) {
System.out.print(chars);
}
}
I am looking for a way to create a method with the initial state in while loop, which will count the length of each word in a string using I want the output to be something along the lines of:
hello world how are you
There are 0 words of length 0
There are 0 words of length 1
There are 0 words of length 2
There are 3 words of length 3
There are 0 words of length 4
There are 2 words of length 5
This is my code so far it sort of does the job but not the way i want it too
import java.util.Scanner;
import java.util.StringTokenizer;
public class Brown_Matthew_13117002{
public static int count(String s, int len){
int result=0;
StringTokenizer st=new StringTokenizer(s,"[ ,;]");
[Code] ....
The output would end up being :
hello
There are 0 words of length 0
world
There are 0 words of length 1
how
There are 0 words of length 2
are
There are 3 words of length 3
you
There are 0 words of length 4