I'm new to Java. I am tasked with creating a menu program, one option is to generate a username in the form of first initial and surname.
The method is stringOperation(String f, String s)
Variables are fName and sName.
Here is the code. I have highlighted the areas I need help with. The rest of the code is OK, I think. This is a section of the pseudocode that explains what is required:
stringOperation(String f, String s)
- 3.1.1 Assign first character of first initial to variable using
f.substring(start position, length of string). - 3.1.2 Concatenate first initial with users surname.
- 3.1.3 print username to console.
import java.util.Scanner; // imports scanner class
public class Assessment {
public static void main(String[] args) { //main method
menu(); //call menu method
}
public static void menu() { //method to display menu options
int choice;
String fName;
String sName;
Scanner sc = new Scanner(System.in);
//displays menu options
System.out.println("Welcome");
System.out.println("1. Username");
System.out.println("2. Factorial");
System.out.println("3. Area of triangle");
System.out.println("4. Circumference of circle");
System.out.println("5. Exit");
//asks for user input
do {
System.out.println("Enter your first name");
fName = sc.next();
System.out.println("Enter your surname");
sName = sc.next();
System.out.println("Thank you. Now enter a selection (1-5):");
choice = sc.nextInt();
//menu loop
switch (choice) {
case 1:
**stringOperation(String fName, String sName);**
break;
case 2:
numberFactorial();
break;
case 3:
areaTriangle();
break;
case 4:
circumferenceCircle();
break;
}
}while (choice!=5);
}
**//stringOperation method
private static void stringOperation(String f, String s) {
String initial = f.substring(0,1);
String username = initial s;
System.out.println("Your username is " initial s);
}**
public static void numberFactorial() { //method to calculate factorial of a number
//variables
int number;
int factorial = 1;
int i;
//input
Scanner sc = new Scanner(System.in);
System.out.println("Please enter a number: ");
number = sc.nextInt();
//for loop
for (i = 1; i <= number; i ) {
factorial = factorial * i;
}
System.out.println("Factorial of " number " is " factorial);
}
public static void areaTriangle ()//method to calculate area of a triangle
{ //input
Scanner sc = new Scanner(System.in);
//variables
double width;
double height;
double area;
//input
System.out.println("Enter the width: ");
width = sc.nextInt();
System.out.println("Enter height: ");
height = sc.nextInt();
area = (height * width) / 2;
System.out.println("The area is :" area);
}
public static void circumferenceCircle ()//method to calculate circumference of a circle
{ //variables
double radius;
double circumference;
Scanner sc = new Scanner(System.in);
System.out.println("Enter radius: ");
radius = sc.nextDouble();
circumference = Math.PI * 2 * radius;
System.out.println("The circumference is : " circumference);
}
}
CodePudding user response：
If you want to make the method cleaner you could do something like this
private static void stringOperation(String f, String s) {
System.out.println("Your username is " f.substring(0,1) s)
}
If you need to refer back to the new username then have a global variable that your method can set to refer to later like this.
private static void stringOperation(String f, String s) {
Assessment.username = f.substring(0,1) s;
System.out.println("Your username is " Assessment.username);
}
CodePudding user response：
I hope this is what you are looking for.
public class Answer {
public static void main(String[] args) { //main method
menu(); //call menu method
}
public static void menu() { //method to display menu options
int choice;
String firstName;
String surName;
Scanner sc = new Scanner(System.in);
//displays menu options
System.out.println("Welcome");
System.out.println("1. Username");
System.out.println("2. Factorial");
System.out.println("3. Area of triangle");
System.out.println("4. Circumference of circle");
System.out.println("5. Exit");
//asks for user input
do {
System.out.println("Enter your first name");
firstName = sc.next();
System.out.println("Enter your surname");
surName = sc.next();
System.out.println("Thank you. Now enter a selection (1-5):");
choice = sc.nextInt();
//menu loop
switch (choice) {
case 1:
stringOperation(firstName, surName);
break;
case 2:
numberFactorial();
break;
case 3:
areaTriangle();
break;
case 4:
circumferenceCircle();
break;
}
}while (choice!=5);
System.exit(0);
}
//stringOperation method
private static void stringOperation(String firstName, String surName) {
//3.1.1 Assign first character of first initial to variable using f.substring(start position, length of string).
String initial = firstName.substring(0, firstName.length() - (firstName.length() - 1)); // used this because of 3.1.1
String username = initial surName;
System.out.println("Your username is " username);
}
public static void numberFactorial() {
int number;
int factorial = 1;
int i;
//input
Scanner sc = new Scanner(System.in);
System.out.println("Please enter a number: ");
number = sc.nextInt();
//for loop
for (i = 1; i <= number; i ) {
factorial = factorial * i;
}
System.out.println("Factorial of " number " is " factorial);
}
public static void areaTriangle () { //input
Scanner sc = new Scanner(System.in);
//variables
double width;
double height;
double area;
//input
System.out.println("Enter the width: ");
width = sc.nextInt();
System.out.println("Enter height: ");
height = sc.nextInt();
area = (height * width) / 2;
System.out.println("The area is :" area);
}
public static void circumferenceCircle () {
double radius;
double circumference;
Scanner sc = new Scanner(System.in);
System.out.println("Enter radius: ");
radius = sc.nextDouble();
circumference = Math.PI * 2 * radius;
System.out.println("The circumference is : " circumference);
}
}