Question

8.15 *zyLab: Method Library (Required & Human Graded)

This code works but there are some problems that need to be corrected. Your task is to complete it to course style and documentation standards CS 200 Style Guide. This project will be human graded.

This class contains a set of methods. The main method contains some examples of using the methods. Figure out what each method does and style and document it appropriately. The display method is done for you and doesn't need any changes. The methods to improve are named first, second, third, and fourth.

import java.util.Arrays;

import java.util.Scanner;

public class MethodLibrary {

public static void main(String args[]) {

System.out.println("MethodLibrary");

System.out.println("Example use of methods");

int[] smallNums1 = {2, 1, 7, 4, 3};

display("display:", smallNums1);

char [] characters = {'a','b','c','d','e','f'};

first( characters, 2);

System.out.print("after first: ");

System.out.println(characters);

int[] bigNums = {1234, 20001, 3764, 20947, 9099};

System.out.println("after second: " + second(bigNums));

int[] smallNums2 = { 8, 7, 3, 4, 5, 0, 1};

third(smallNums2, true);

System.out.println("after third: " + Arrays.toString(smallNums2));

Scanner i = new Scanner("-5 0 error 25 happy 20 14 end");

int r = fourth( i, "Enter a number between 1 and 20, inclusive", 1, 20);

}

/**

* This method prints the description followed by the contents of list.

* The list begins with '[', ends with ']' and each element is separated

* with ', '.

* Example: display( "a description", new int[]{1,2,3})

* a description [1, 2, 3]

* @param description The text printed out before the list of integers.

* @param list The array of integers to be printed.

*/

public static void display(String description, int[] list) {

System.out.print(description);

System.out.print(" [");

for (int i = 0; i < list.length; i++) {

if (i > 0) {

System.out.print(", ");

}

System.out.print(list[i]);

}

System.out.println("]");

}

public static void first(char[] r, int b) {

for (int i = 0 ; i < b; i++)

{ char s = r[r.length - 1];

for (int j = r.length - 1; j > 0; j--) {r[j] = r[j - 1]; }

r[0] = s; }

}

public static int second(int[] z) {

int g; g = z[0];

for (int i = 0; i < z.length; i++) { if ( z[i] > g) { g = z[i]; } }

return g;

}

public static void third(int[] t, boolean stl) {

int m;

for (int i = 0; i < t.length; i++) {

for (int j = i + 1; j < t.length; j++) {

if (stl) { if (t[i] > t[j]) { m = t[i]; t[i] = t[j]; t[j] = m;}

} else {if (t[i] < t[j]) {

m = t[i]; t[i] = t[j]; t[j] = m;

}

}

}

}

}

public static int fourth(Scanner a, String b, int c, int d) {

System.out.println(b); boolean v = false; int r = 0;

do {if (a.hasNextInt()) { r = a.nextInt();

if (r >= c && r <= d) { v = true;

} else {System.out.println("Value must be between " + c + " and " + d + ".");

}

} else { a.next(); } } while (!v); return r;

}

}

Answer 1

I would make my changes bold and italic for better understanding. Please leave an upvote if you like this answer. Thank you.

Code:

import java.util.Arrays;
import java.util.Scanner;
public class Main {
public static void main(String args[]) {
System.out.println("MethodLibrary");
System.out.println("Example use of methods");
int[] smallNums1 = {
2,
1,
7,
4,
3
};
display("display:", smallNums1);
char[] characters = {
'a',
'b',
'c',
'd',
'e',
'f'
};
first(characters, 2);
System.out.print("after first: ");
System.out.println(characters);
int[] bigNums = {
1234,
20001,
3764,
20947,
9099
};
System.out.println("after second: " + second(bigNums));
int[] smallNums2 = {
8,
7,
3,
4,
5,
0,
1
};
third(smallNums2, true);
System.out.println("after third: " + Arrays.toString(smallNums2));
Scanner i = new Scanner("-5 0 error 25 happy 20 14 end");
int r = fourth(i, "Enter a number between 1 and 20, inclusive", 1, 20);
}
/**
* This method prints the description followed by the contents of list.
* The list begins with '[', ends with ']' and each element is separated
* with ', '.
* Example: display( "a description", new int[]{1,2,3})
* a description [1, 2, 3]
* @param description The text printed out before the list of integers.
* @param list The array of integers to be printed.
*/
public static void display(String description, int[] list) {
System.out.print(description);
System.out.print(" [");
for (int i = 0; i < list.length; i++) {
if (i > 0) {
System.out.print(", ");
}
System.out.print(list[i]);
}
System.out.println("]");
}
/**
* This method takes a string and rotates it a certain number of times.
* Example first(abcdef,2)
* The string abcdef would become efabcd
* @param The string in which the characters are to be rotated.
* @param The number of times for which the characters would be rotated.
*/
public static void first(char[] r, int b) {
for (int i = 0; i < b; i++) {
char s = r[r.length - 1];
for (int j = r.length - 1; j > 0; j--) {
r[j] = r[j - 1];
}
r[0] = s;
}
}
/**
* This method returns the largest element in a given list.
* Example second(new int[]{2,3,4,1,55})
* 55
* @param The list from which we want to get the lagrest element.
*/
public static int second(int[] z) {
int g;
g = z[0];
for (int i = 0; i < z.length; i++) {
if (z[i] > g) {
g = z[i];
}
}
return g;
}
/**
* This method take a list as an argument
* and sorts it in ascending or descending order on the basis a boolean variable.
* Example third(new int[]{3,1,2,5,4},true)
* [1,2,3,4,5]
* Example third(new int[]{3,1,2,5,4},false)
* [5,4,3,2,1]
* @param the integer array method wants to sort
* @param boolean value to decide the order of sorting.
*/
public static void third(int[] t, boolean stl) {
int m;
for (int i = 0; i < t.length; i++) {
for (int j = i + 1; j < t.length; j++) {
if (stl) {
if (t[i] > t[j]) {
m = t[i];
t[i] = t[j];
t[j] = m;
}
} else {
if (t[i] < t[j]) {
m = t[i];
t[i] = t[j];
t[j] = m;
}
}
}
}
}
/**
* This method take a list of inputs and prints out a error message
* if any integer in our input is not between the given two numbers.
* It also prints out required input at the start.
* Example fourth(new Scanner("-5 0 error 25 happy 20 14 end"),
* "Enter a number between 1 and 20, inclusive", 1, 20);
* Enter a number between 1 and 20, inclusive
* Value must be between 1 and 20.
* Value must be between 1 and 20.
* Value must be between 1 and 20.
* @param input values
* @param String to print at beginning
* @param minimum value
* @param maximum value
*/
public static int fourth(Scanner a, String b, int c, int d) {
System.out.println(b);
boolean v = false;
int r = 0;
do {
if (a.hasNextInt()) {
r = a.nextInt();
if (r >= c && r <= d) {
v = true;
} else {
System.out.println("Value must be between " + c + " and " + d + ".");
}
} else {
a.next();
}
} while (!v);
return r;
}
}

Code screenshot:

Solution ends.

Please comment and let me know if you have any further doubts. Please upvote this answer if you like it.

Thank you.

Have a good day.