Question

Write a Java program that checks the properness of a given variable name. More specifically, your program should specify whether a user-entered variable name is

1. illegal (no spaces allowed, must begin with a letter)
2. legal, but uses poor style (should only use letters or digits)
3. good

You don’t need to check for an uppercase letter for the first letter in the second word, third word, etc.

Sample session:

This program checks the properness of a proposed Java variable name.
Enter a variable name (q to quit): streetAddress2
Good!
Enter a variable name (q to quit): street address2
Illegal.
Enter a variable name (q to quit): StreetAddress2
Good!
Enter a variable name (q to quit): 2ndStreetAddress
Illegal.
Enter a variable name (q to quit): street$address$2
Legal, but uses poor style.
Enter a variable name (q to quit): q

Answer 1

PLEASE GIVE IT A THUMBS UP

nikhil@nikhil-Vostro-15-3568: -/Desktop/CODE File Edit View Search Terminal Help nikhil@nikhil-Vostro-15-3568:-/Desktop/CODE$ javac A.java nikhil@nikhil-Vostro-15-3568:-/Desktop/CODE$ java A This program checks the properness of a proposed Java variable name. Enter a variable name (9 to quit): streetAddress2 Good! Enter a variable name (9 to quit): street address2 Illegal Enter a variable name (a to quit): StreetAddress2 Good! Enter a variable name (9 to quit): 2ndStreetAddress Illegal Enter a variable name (a to quit): streetsaddress$2 Legal, but uses poor style Enter a variable name (a to quit): 4 nikhil@nikhil-Vostro-15-3568:~/Desktop/CODE$ I

import java.util.*;
class A{
   public static void main(String[] args) {
       Scanner sc = new Scanner(System.in);
       System.out.println("This program checks the properness of a proposed Java variable name.");
       while(true){
           System.out.print("Enter a variable name (q to quit): ");
           String s = sc.nextLine();
           if(s.equals("q"))
               break;
           if(s.contains(" ") || (s.charAt(0)>='0' && s.charAt(0)<='9'))
           {
               System.out.println("Illegal");
               continue;
           }
           int flag=0;
           for(int i=0;i<s.length();i++){
               if(((s.charAt(i)>='a' && s.charAt(i)<='z') || (s.charAt(i)>='A' && s.charAt(i)<='Z') || (s.charAt(i)>='0' && s.charAt(i)<='9'))==false)
               {                  
                   System.out.println(" Legal, but uses poor style");
                   flag=1;
                   break;
               }
           }
           if(flag==1)
               continue;
           System.out.println("Good!");
       }
   }
}

1 2 3 5 6 7 8 import java.util.; class A{ public static void main(String[] args) { Scanner sc = new Scanner(System.in); System.out.println("This program checks the properness of a proposed Java variable name."); while(true){ System.out.print("Enter a variable name (q to quit): "); String s = sc.nextLine(); if(s.equals("")) break; if(s. contains(" ") || (s.charAt()>='0' && s.charAt()<='9')) { System.out.println("Illegal"); continue; 10 11 13 14 15 16 18 19 26 21 22 int flag=0; for(int i=0;i<s.length();i++){ if(((s.charAt(i)>='a' && s.charAt(i)<='z') || (s.charAt(i)>='A' && s.charAt(i)<='Z') || (s.charAt(i)>='0' && s.charAt(i)<='9'))=false) System.out.println(" Legal, but uses poor style"); flag=1; break; 24 } if(flage=1) continue; System.out.println("Good!");