Question

THE LANGUAGE IS JAVA

Download the class ArrayManager.java and fill out the method shells with the specifications below. After creating the methods 2) through 5), test them by running the application. The main method allows users to enter a command and, when necessary, additional command specifications.

1) a method displayArray:

• accepts as a parameter an int array named data
• prints the array elements to the console, separated by commas and spaces, with the entire array enclosed in braces, e.g., the array [0, 1, 2] should display as {0, 1, 2}

2) a method expandIntArray:

• accepts as a parameter an int array named data
• creates a new int array twice as large as data
• copies every int value from data into the same index in the new array
• the other indexes in the new array should be zeroes
• returns the new array

3) a method shrinkIntArray:

• accepts as a parameter an int array named data
• creates a new int array half as large as data
• for every index in the new array, copies the corresponding int value from data into it
• returns the new array

4) a method insertValue:

• accepts as parameters an int array named data, an int named value, and an int named index
• creates a new array one element larger than data
• for every index < index, copies the value from data into the new array
• copies value into the new array's index element

• for every index > index, copies the value from data into the new array's next index, i.e., copies from index x in data to index x+1 in the new array
• returns the new array

5) a method removeValue:

• accepts as parameters an int array named data and an int named index
• creates a new array one element smaller than data
• for every index < index, copies the value from data into the new array

• for every index > index, copies the value from data into the new array's previous index, i.e., copies from index x in data to index x-1 in the new array
• returns the new array

HERE'S "ArrayManager.java" code:

import java.util.Scanner;

public class ArrayManager {
        int[] data = new int[0];
        
        public static void main(String[] args) {
                ArrayManager am = new ArrayManager();
                while(true) {
                        System.out.println("please enter a command: display, expand, shrink, insert, remove, expand");
                        String command = new Scanner(System.in).next();
                        switch(command) {
                                case "display": am.displayArray(am.data); break;
                                case "expand": am.data = am.expandIntArray(am.data); break;
                                case "shrink": am.data = am.shrinkIntArray(am.data); break;
                                case "insert": System.out.println("please enter the new value");
                                int value = new Scanner(System.in).nextInt();
                                System.out.println("please enter the insertion index");
                                int insert = new Scanner(System.in).nextInt();
                                am.data = am.insertValue(am.data, value, insert); break;
                                case "remove": System.out.println("please enter the removal index");
                                int delete = new Scanner(System.in).nextInt();
                                am.data = am.removeValue(am.data, delete); break;
                        }
                }
        }

        void displayArray(int[] data) {
                
        }
        
        int[] expandIntArray(int[] data) {
                int[] data2 = null;
                return data2;
        }
        
        int[] insertValue(int[] data, int value, int index) {
                int[] data2 = null;
                return data2;
        }
        
        int[] removeValue(int[] data, int index) {
                int[] data2 = null;
                return data2;
        }

        int[] shrinkIntArray(int[] data) {
                int[] data2 = null;
                return data2;
        }
}

Answer 1

GIVEN BELOW ARE THE COMPLETED VERSIONS OF THE AFOREMENTIONED FUNCTIONS:

void displayArray(int[] data) {

for(int i=0; i<data.length(); i++)
      { System.out.println(data[i]);       
        }

int[] expandIntArray(int[] data) {

   int len= 2* data.length();
                int[] data2 = new int [len];

   for(int i=0; i<len; i++)
   {
       if(!i<data.length())
           data2[i]=0;
       else
           data2[i]=data[i];
   }
                return data2;
        }

   int[] shrinkIntArray(int[] data) {
   int len=data.length()/2;
                int[] data2 = new int [len];
   for(int i=0; i<len; i++)
   {
       data2[i]=data[i];
   }
                return data2;
        }

int[] insertValue(int[] data, int value, int index) {
                int len= data.length()+1;
                int[] data2 = new int[len];
  
   for(int i=0; i<(len-1); i++)
   {
       if(i<index)
           data2[i]=data[i];
       else if(i>index)
           data2[i+1]=data[i];
   }
       data2[index]=value;
                return data2;
        }

   int[] removeValue(int[] data, int index) {
                int len= data.length()-1;
                int[] data2 = new int [len];
   for(int i=0; i<len; i++)
   {
       if(i<index)
           data2[i]=data[i];
       else if(i>index)
           data2[i]= data[i-1];
   }

                return data2;
        }