I do not know how to display entries entered by user, and also to match and sort them.
import java.util.Scanner;
public class Case1
{
public static void main(String[] args) {
Scanner in=new Scanner (System.in);
System.out.println("Input a size of an array: ");
int size = in.nextInt();
int num[]=new int[size];
int i=0;
for (i=0;i<num.length;i++) {
System.out.println("Input a number: ");
num[i]=in.nextInt();
}
for (int c=0;i<num.length;c++){
for (int a=0; a<num.length;a++){
if(num[c]>num[a]){
int temp = num[c];
num[c]= num[a];
num[a]=temp;
}
}
}
for (int d=0;i<num.length;d++){
int value = 0;
if(value==num[i]) {
System.out.println("Match Found!");
}
}
}
}
help please.
It should look like this ->
import java.util.Scanner;
public class Case1
{
public static void main(String[] args) {
Scanner in=new Scanner (System.in);
System.out.println("Input a size of an array: ");
int size = in.nextInt();
int num[]=new int[size];
int i=0;
for (i=0;i<num.length;i++) {
System.out.println("Input a number: ");
num[i]=in.nextInt();
}
// DISPLAY ENTRIES
System.out.println("You entered the following entries.");
for (int index=0; index<num.length; index++) {
System.out.print(index + ": " + num[index] + " ");
}
// END DISPLAY ENTRIES
for (int c=0;c<num.length;c++){ // Changed i to c
for (int a=0; a<num.length;a++){
if(num[c]>num[a]){
int temp = num[c];
num[c]= num[a];
num[a]=temp;
}
}
}
for (int d=0;d<num.length;d++){ // Changed i to d
int value = 0;
if(value==num[d]) { // Changed i to d
System.out.println("Match Found!");
}
}
}
}
This should work, but when you asked in your question about matching, did you want to match each entry with 0 (which makes no sense) or did you want to compare each entry to 0?
Related
So, this below is my code:
public class StudentRun {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
String[] names = new String[50];
int[] rolls = new int[50];
System.out.print("Do you want to register a student ?(yes/no): ");
String res = sc.nextLine();
while((res.toUpperCase()).equals("YES")) {
System.out.print("Enter the student's name: ");
String n = sc.nextLine();
for(int i=1; i<50; i++) {
names[i] = n;
}
System.out.print("Enter their roll number: ");
int r = sc.nextInt();
for(int j=0; j<50; j++) {
rolls[j] = r;
}
}
for(int a=0; a<50; a++) {
System.out.println(names[a]);
System.out.println(rolls[a]);
}
}
}
What I want is to happen is that, the program should keep registering students name and roll no. until the array is full or the user ends it. How do I do it ? I got that far
You need to have the "continue" question in the while loop, and you don't need the for loop every time you insert a name.
public class StudentRun {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
String[] names = new String[50];
int[] rolls = new int[50];
int index = 0;
while(true) {
System.out.print("Do you want to register a student ?(yes/no): ");
String res = sc.nextLine();
if(res.toUpperCase().equals("NO") || index == 50)
break;
System.out.print("Enter the student's name: ");
String n = sc.nextLine();
names[index] = n;
System.out.print("Enter their roll number: ");
int r = sc.nextInt();
rolls[index] = r;
index++;
}
for(int i=0; i<50; i++) {
System.out.println(names[i]);
System.out.println(rolls[i]);
}
}
}
A common approach when using fixed sized arrays is to use a separate int variable to track the current index position for a new item, as well as the total used slots in the array:
import java.util.*;
class Main {
public static void main(String[] args)
{
Scanner sc = new Scanner(System.in);
int size = 50;
String[] names = new String[size];
int[] rolls = new int[size];
int counter = 0;
String res = "";
do {
System.out.print("Do you want to register a student ?(yes/no): ");
res = sc.nextLine().toUpperCase();
if (res.equals("YES")) {
System.out.print("Enter the student's name: ");
names[counter] = sc.nextLine();
System.out.print("Enter their roll number: ");
rolls[counter] = sc.nextInt();
sc.nextLine(); // clear enter out of buffer;
counter++;
}
} while (counter < size && res.equals("YES"));
for(int a=0; a<counter; a++) {
System.out.print(names[a] + " : ");
System.out.println(rolls[a]);
}
}
}
import java.util.Scanner;
public class TeacherCoins {
public static void main(String[] args){
int k;
System.out.print("Enter total number of coins :");
Scanner sc = new Scanner(System.in);
k =sc.nextInt();
int [] arr= new int[k-1];
System.out.print("Enter array :");
for(int i=0;i<=(k-1);i++)
{
Scanner sc1 = new Scanner(System.in);
arr[i] =sc1.nextInt();
}
for(int element :arr)
{
System.out.println("Print array");
System.out.println(element);
}
}
I am giving output using Scanner class. But is not printing the array.
You don't need to declare the Scanner again inside the loop. Another thing that you should do to be sure of your code, is to have this condition on the loop if i < arr.length. Lastly, I moved the "Print array" message outside the last for.
public class TeacherCoins {
public static void main(String[] args){
int k;
System.out.print("Enter total number of coins :");
Scanner sc = new Scanner(System.in);
k =sc.nextInt();
int [] arr = new int[k];
System.out.print("Enter array :");
for(int i=0; i<arr.length; i++) {
arr[i] =sc1.nextInt();
}
System.out.println("Print array");
for(int element :arr){
System.out.println(element);
}
}
}
There are two problems with this code,
1. You don't need to create a new Scanner object for each user input.
2. You are declaring an array size of k-1 and then asking user input k times.
public static void main(String[] args) {
int k;
System.out.print("Enter total number of coins :");
Scanner sc = new Scanner(System.in);
k = sc.nextInt();
int[] arr = new int[k]; // To store k elements, you need k sized array
System.out.print("Enter array :");
for (int i = 0; i <= (k - 1); i++) {
// Scanner sc1 = new Scanner(System.in); / / Not required here
arr[i] = sc.nextInt();
}
System.out.println("Print array");
for (int element : arr) {
System.out.println(element);
}
}
There is only one problem in your code you are declaring the size of array as k-1 instead declare it for k elements.You just need to give each inputs in new line. For more refer this :Scanner class.
And your for each loop is correct and working.
import java.util.Scanner;
public class TeacherCoins {
public static void main(String[] args){
int k;
System.out.print("Enter total number of coins :");
Scanner sc = new Scanner(System.in);
k =sc.nextInt();
int [] arr= new int[k];//it was giving java.lang.ArrayIndexOutOfBoundsException
System.out.print("Enter array :");
for(int i=0;i<=(k-1);i++)
{
Scanner sc1 = new Scanner(System.in);//not required
arr[i] =sc1.nextInt();//use arr[i] =sc.nextInt();
}
for(int element :arr)
{
System.out.println("Print array");
System.out.println(element);
}
}
}
Above code will work. But you don't need new scanner objects for taking input, creating only single object will work.
import java.util.Scanner;
public class TeacherCoins {
public static void main(String[] args) {
int k;
System.out.print("Enter total number of coins :");
Scanner sc = new Scanner(System.in);
k = sc.nextInt();
int[] arr = new int[k];
System.out.print("Enter array :");
for (int i = 0; i < arr.length; i++) {
arr[i] = sc.nextInt();
}
sc.close();
System.out.println("Print array");
for (int element : arr) {
System.out.println(element);
}
for (int i = 0; i < arr.length; i++) {
int count = 0;
for (int j = 0; i < arr.length; j++) {
arr[i] = arr[j];
count++;
}
System.out.println(arr[i] + " " + count);
}
}
}
Below is the code. After entering the array, the console just goes blank and does not further output the array:
import java.util.Scanner;
public class advancedArrays {
public static void main(String[] args) {
System.out.println("Provide us the size of the array:");
Scanner scanner = new Scanner(System.in);
int value = scanner.nextInt();
int i = 0;
int[] array = new int[value];
System.out.println("Enter the array:");
Scanner input = new Scanner(System.in);
while(input.hasNextInt()) {
array[i] = input.nextInt();
i++;
}
System.out.println("Array entered:");
for(i=0;i<value;i++)
{
System.out.println(array[i]);
}
input.close();
scanner.close();
}
}
Output:
Provide us the size of the array:
5
Enter the array:
1 2 3 4 5
you are stuck in the "reading the array" part because of this
while (input.hasNextInt()) {
array[i] = input.nextInt();
hint: you know the size of the array, then why don't you do a for loop same as you did for printing out the array's content?? like:
for (int j = 0; j < value; j++) {
array[i] = scanner.nextInt();
i++;
}
The problem is that with the while loop that you keep it waiting for more integers, it is better to convert to a normal for loop with condition on the entered array size value.
Also there is no need to use two scanner objects
public static void main(String[] args) {
System.out.println("Provide us the size of the array:");
Scanner scanner = new Scanner(System.in);
int value = scanner.nextInt();
int i = 0;
int[] array = new int[value];
System.out.println("Enter the array:");
for (int j = 0; j < value; j++) {
if (scanner.hasNextInt()) {
array[i] = scanner.nextInt();
i++;
}
}
System.out.println("Array entered:");
for (i = 0; i < value; i++) {
System.out.println(array[i]);
}
scanner.close();
}
package Main;
import java.util.Scanner;
public class advancedArrays {
public static void main(String[] args) {
System.out.println("Provide us the size of the array:");
Scanner scanner = new Scanner(System.in);
int value = scanner.nextInt();
int i = 0;
int[] array = new int[value];
System.out.println("Enter the array:");
Scanner input = new Scanner(System.in);
while(input.hasNextInt()) {
array[i] = input.nextInt();
i++;
//Changed Code
if (i == value) {
break;
}
}
System.out.println("Array entered:");
for(i=0;i<value;i++)
{
System.out.println(array[i]);
}
input.close();
scanner.close();
}
}
Fixed code, you were stuck reading your inputs for your array because you never checked if your inputs were the length of your array.
Fixed code.
if (i == value) {
break;
}
This is my program and every time it is asking me to input the array.
I want to input a array once and process on that array.
But this program is asking me to input array again.
from method named "first" I just want to return array and use that array in two different methods add and delete. But it is always asking me to input all the elements of array that is every time the first method is running while i call any add or delete method from main method.
package Program;
import java.util.Arrays;
import java.util.Scanner;
public class Functionality {
public static int[] first( )
{
System.out.println("Enter the number of element in array");
Scanner num = new Scanner(System.in);
int data = num.nextInt();
//return data;
Scanner ar = new Scanner(System.in);
int arr[] = new int[data];
System.out.println("Enter "+data+" Numbers");
for(int i =0; i<data; i++){
System.out.println("Enter NUmber :"+(i+1));
arr[i] = num.nextInt();
}
System.out.println();
System.out.println(Arrays.toString(arr));
return arr;
}
public static void main(String[] args) {
add();
delete();
}
static void add(){
int arr[]=first();
System.out.println("Enter the number you want to add");
Scanner one = new Scanner(System.in);
int naya = one.nextInt();
for(int i = 0; i<=arr.length-1; i++){
arr[i]= arr[i] + naya;
}
System.out.println("The added array is");
System.out.println(Arrays.toString(arr));
}
static void delete(){
int arr[]=first();
System.out.println("Enter the number you want to substract");
Scanner two = new Scanner(System.in);
int arko = two.nextInt();
for(int i =0; i <= arr.length-1; i++ ){
arr[i]=arr[i]-arko;
}
System.out.println("The Substracted array is");
System.out.println(Arrays.toString(arr));
}
You should obtain reference to an array and passing it during subsequent methods invocations.
This should do the trick:
class Functionality {
static int[] first() {
System.out.println("Enter the number of element in array");
Scanner num = new Scanner(System.in);
int data = num.nextInt();
//return data;
Scanner ar = new Scanner(System.in);
int arr[] = new int[data];
System.out.println("Enter " + data + " Numbers");
for (int i = 0; i < data; i++) {
System.out.println("Enter NUmber :" + (i + 1));
arr[i] = num.nextInt();
}
System.out.println();
System.out.println(Arrays.toString(arr));
return arr;
}
public static void main(String[] args) {
int arr[] = first();
add(arr);
delete(arr);
}
static void add(int arr[]) {
System.out.println("Enter the number you want to add");
Scanner one = new Scanner(System.in);
int naya = one.nextInt();
for (int i = 0; i <= arr.length - 1; i++) {
arr[i] = arr[i] + naya;
}
System.out.println("The added array is");
System.out.println(Arrays.toString(arr));
}
static void delete(int arr[]) {
System.out.println("Enter the number you want to substract");
Scanner two = new Scanner(System.in);
int arko = two.nextInt();
for (int i = 0; i <= arr.length - 1; i++) {
arr[i] = arr[i] - arko;
}
System.out.println("The Substracted array is");
System.out.println(Arrays.toString(arr));
}
}
Your program is asking You every time to input array, because every time You invoke method first() new array is being created
I have to write a program having 3 parallel arrays one that holds 4 digit student ID the second the student Name and the last one that holds the GPA and the size of the arrays have to be 10
also the program be able to do a Student ID search and if it doesnt exist to show an error message
the first part works fine but when it comes to the searching it doesnt work
import java.util.ArrayList;
import javax.swing.JOptionPane;
import java.util.Scanner;
public class StudentIDArray
{
public static void main(String[] args)
{
int option;
String inputString;
inputString = JOptionPane.showInputDialog("Welcome"
+" Choose the option you will like"
+ " \n1. Enter Student Information "
+ "\n2. Search for Student");
option = Integer.parseInt(inputString);
if(option ==1)
{
Scanner in = new Scanner(System.in);
System.out.println("Enter the name of the Student");
String[] studentname = new String[10];
for(int i =0; i<studentname.length; i++)
{
studentname[i] = in.nextLine();
}
System.out.println("Enter the 4 digit Student ID");
int[] studentID = new int[10];
for(int x=0; x<studentID.length; x++)
{
studentID[x] = in.nextInt();
}
System.out.println("Enter the Student's Grade Point Average");
int[] gpa = new int[10];
for(int y=0; y<studentID.length; y++)
{
gpa[y] = in.nextInt();
}
}
else
{
searching();
}
}
public static void searching()
{
int idnumber,
results;
int[]studentID = null;
String inputString;
inputString = JOptionPane.showInputDialog("Please Enter the ID number");
idnumber = Integer.parseInt(inputString);
results = sequentialSearch(studentID, idnumber);
if (results == -1)
{
System.out.println("no information");
}
else
{
System.out.println("yeii congrats");
}
}
public static int sequentialSearch(int[] studentID, int value)
{
int index;
int element;
boolean found;
index =0;
element = -1;
found = false;
while(!found && index < studentID.length)
{
if (studentID[index] == value)
{
found = true;
element = index;
}
index++;
}
return element;
}
}
The primary issue is that you are declaring the studentID array locally to your methods.
Make it a class member instead (an instance member would be preferred, but all your methods are static), so that your methods are working on the same array, not on different ones:
public class StudentIDArray
{
private static int[] studentID = new int[10];
...
Note that this limits the number of entries to the size of the array and you will get exceptions if you exceed these limits. Consider using a Vector or an ArrayList instead.
searching(studentID);
Pass the studentID array to the searching method instead of declaring it again.
public static void searching(int[] studentID)
{
int idnumber,
results;
//int[]studentID = null;
String inputString;
inputString = JOptionPane.showInputDialog("Please Enter the ID number");
idnumber = Integer.parseInt(inputString);
results = sequentialSearch(studentID, idnumber);
if (results == -1)
{
System.out.println("no information");
}
else
{
System.out.println("yeii congrats");
}
}
public static int sequentialSearch(int[] studentID, int value)
{
int index;
int element;
boolean found;
index =0;
element = -1;
found = false;
while(!found && index < studentID.length)
{
if (studentID[index] == value)
{
found = true;
element = index;
}
index++;
}
return element;
}
A better approach would be to keep it as a static/class variable as #Andreas pointed out.
These are the Running Steps of Program....
First Step => Enter Size of Array.
Second Step => Enter Member of Array.
Third Step => Enter Searching Integer of Array.
import java.util.Scanner;
public class Searching
{
public static void main(String[] args)
{
int temp =-1;
Scanner user_input=new Scanner(System.in);
System.out.println("Enter Size Of Array ");
int Size=user_input.nextInt();
int[] a=new int[Size];
//Scan input Array.
System.out.println("Enter element Of an Array...");
for(int j=0;j<Size;j++)
{
a[j]=user_input.nextInt();
}
System.out.println("The contents of the Array are :");
//Print input Arrray
for(int i=0;i<a.length;i++)
{
System.out.println("array[" + i + "] = " + a[i]);
}
System.out.println("Enter Integer For Searching..");
int Search=user_input.nextInt();
//Searching in an Array.
for(int index=0;index<a.length; index++)
{
if(a[index]==Search)
{
temp=index;
break;
}
}
if(temp!=-1)
{
System.out.println(" The search element is : " + Search);
System.out.println(" It is found in the array at position : " + temp);
}
else
System.out.println("\n Element not Found..");
}
}