Question

For this Lab you have to implement a classBuilder. Your Builder class should have instance variable name. , Supply a constructor method for your Builder class and the following methods: getName(), makeRow(int n, String s), printPyramid(int n, String s).

Examining the problem, we need to create aBuilder class, declare Builderclass as follows

public class Builder {

}

Inside the Builder class, declare aString variable called name.

Step 3: Defining the constructors:

Remember that the purpose of a constructor is to assign valid values to all the data members.

public Builder (String name) {
    // write the segment of code
    // that assigns the parameter value to the private instance variable
}

Step4: Supply the methods

Implement the getName method:

Hint: getter methods often simply return the desired value, which is usually stored in a private instance variable.

public String getName() {
    // write a line of code that returns the name
}

Implement a makeRow method.

Given an integer n and strings, the makeRow method returns an other String that has n copies ofs in a row. For eaxmple makeRow(5, "abc") should return"abcabcabcabcabc".

public String makeRow(int n, String s) {
    // Given an int n and string s, 
    // return a string that represents n copies of s in one row.
    //Example: n = 5, s = “*”, return a string “*****”
}

Write a method called printPyramid that given an odd integer n and a string s, prints (not returns) a pyramidal shape made out of that strings. The top of the pyramid has a single copy ofs, and each successive row has two additional copies of s. The last row containsn copies of s. For example, calling printPyramid(7, "*"); prints the following lines:

   *   
  ***  
 ***** 
*******

public void printPyramid(int n, String s) {
    // Make use of makeRow method and System.out.println
    // to print the pyramid.
    // note this method does not return anything.
}

Step 5: Calling the constructor of Builder class from the “main” method.

In your Lab7.java file, you will instantiate and use a Builder class object.

import java.util.Scanner;

public class Lab7 {
  public static void main(String[] args) {
    //declare variables where you will store inputs from user 
    -->// declare a Scanner object 
    -->// prompt the user for input string name 
    -->// store the input in the declared variables 
    -->// declare a variable of type Builder named myBuilder
    // and instantiate a brand-new builder object 
    // with the name given by the user above
    -->
  }
}

Hint: Do not forget to import the Scannerpackage at the very top of your program.

Step 6: Calling Builder class methods and display the output

Now (also in the main method) we will call the methods in the Builder class to display the required outputs.

// call the getName() method to get the name of the builder. 
-->

// Ask for integer n from user using Scanner class
System.out.println("Enter a positive integer:");

// Using your builder's makeRow method print a string below,
// Example: =====*****===== with n = 5;
-->

// Ask for odd integer t from user using Scanner class
System.out.println("Enter a positive odd integer :");
// Call the Builder method printPyramid, passing t and "*" as the arguments
// to print pyramid with “*” as a string.
-->

Step 7: Sample Output

Below is an example of what your output should roughly look like when this lab is completed. All text in bold redrepresents user input.

First run:

Name of the builder: AlexThe name of builder is :Alex
Enter a positive integer :5=====*****=====

Enter a positive odd integer :7

   *   
  ***  
 ***** 
*******

Second run:

Name of the builder: BobThe name of builder is :Bob
Enter a positive integer :3===***===

Enter a positive odd integer :11 * 
    *** 
   ***** 
  *******
 *********
***********

Answer 1

// Builder.java

public class Builder {
private String name;
public Builder(String name) {
// write the segment of code
// that assigns the parameter value to the private instance variable
this.name = name;
}
public String getName() {
// write a line of code that returns the name
return name;
}
public String makeRow(int n, String s) {
// Given an int n and string s,
// return a string that represents n copies of s in one row.
// Example: n = 5, s = “*”, return a string “*****”
String str = "";
for (int i = 0; i < n; i++) {
str += "=";
}
for (int i = 0; i < n; i++) {
str += s;
}
for (int i = 0; i < n; i++) {
str += "=";
}
return str;
}
public void printPyramid(int n, String s) {
int size =n; //use only odd numbers here
for (int i = 1; i <= size; i=i+2) {
int spaceCount = (size - i)/2;
for(int j = 0; j< size; j++) {
if(j < spaceCount || j >= (size - spaceCount)) {
System.out.print(" ");
} else {
System.out.print(s+" ");
}
}
System.out.println();
}
}
}
_______________________________

// Lab10.java

import java.util.Scanner;
public class Lab10 {
public static void main(String[] args) {
//declare variables where you will store inputs from user
String s;
int n;
// declare a Scanner object
/*
* Creating an Scanner class object which is used to get the inputs
* entered by the user
*/
Scanner sc = new Scanner(System.in);
// prompt the user for input string name
System.out.print("Enter String :");
// store the input in the declared variables
s=sc.next();
// declare a variable of type Builder named myBuilder
// and instantiate a brand-new builder object
// with the name given by the user above
Builder b=new Builder(s);
  
// call the getName() method to get the name of the builder.
System.out.println("The name of builder is :"+b.getName());
// Ask for integer n from user using Scanner class
System.out.print("Enter a positive integer:");
// Using your builder's makeRow method print a string below,
// Example: =====*****===== with n = 5;
n=sc.nextInt();
System.out.println(b.makeRow(n, "*"));
// Ask for odd integer t from user using Scanner class
System.out.println("Enter a positive odd integer ,:");
System.out.print("representing number of stars in the base f a pyramid:");
  
// Call the Builder method printPyramid, passing t and "*" as the arguments
// to print pyramid with “*” as a string.
n=sc.nextInt();
b.printPyramid(n,"*");
}
}

__________________________________

Output#1:

Enter String :Alex
The name of builder is :Alex
Enter a positive integer:5
=====*****=====
Enter a positive odd integer ,:
representing number of stars in the base f a pyramid:7
*   
* * *   
* * * * *   
* * * * * * *
________________________

Output#2:

Enter String :Bob
The name of builder is :Bob
Enter a positive integer:9
=========*********=========
Enter a positive odd integer ,:
representing number of stars in the base f a pyramid:21
*   
* * *   
* * * * *   
* * * * * * *   
* * * * * * * * *   
* * * * * * * * * * *   
* * * * * * * * * * * * *   
* * * * * * * * * * * * * * *   
* * * * * * * * * * * * * * * * *   
* * * * * * * * * * * * * * * * * * *   
* * * * * * * * * * * * * * * * * * * * *