1 ≤ N ≤ 100 you forgot this constraints if number is 101

The issue is with the string comparison using == instead of equals. == compares the references, which are very unlikely to be equal. Change to

if(grade.equals("A")){ totalGradePoints += 4; numClasses++; }else if(grade.equals("B")){ ... and it should work. See this answer for a detailed explanation.

As a good practice it is advisable to always use the static string as the object for calling equals on to prevent a NPE:

if("A".equals(grade)){ totalGradePoints += 4; numClasses++; }else if("B".equals(grade)){ ... If you are using Java 7, you can also do a switch statement with strings (though this one will throw an NPE if grade is null):

switch(grade) { case "A": totalGradePoints += 2; numClasses++; break; case "B": ... } And finally, since you are converting only one letter to an integer, to best solution is to convert them to char and for the values between A and D to do totalGradePoints += ('D' - grade.charAt(1)) + 1. So something along those lines would be simplest to read IMO:

while (true) {
final String input = in.next(); if(input == null || input.isEmpty()) break;

final char grade = input.charAt(0);
if(grade >= 'A' && grade <= 'D') {
    totalGradePoints += ('D' - grade) + 1;
} else if(grade == 'F') {
    // no gradepoints for 'F'
} else {
    break;
} //end if - else-if - else statement

++numClasses;

} //end while loop

Java training in chennai | Android training in chennai | Oracle dba Training in Chennai | Python Training in chennai

2nd one is very good and short logic appreciable!!!

;) oh yes you do!

Good idea!

This is my favourite solution. Good stuff.

Its precaution in case you copypaste code with different kind of line and paragraf separators. This command actually tells scanner to ingore these special symbols in the code that you will feed to scanner.

U don't need the final IF

if(n>=2 && n<=5) ans = "Not Weird";

else if(n>=6 && n<=20) ans = "Weird";

else // ANY NUMBER GREATER THAN 20 ans = "Not Weird";

import java.io.; import java.util.; import java.text.; import java.math.; import java.util.regex.*;

public class Solution {

    public static void main(String[] args) {

        Scanner sc=new Scanner(System.in);
        int n=sc.nextInt();            
        String ans="";
        if(n%2==1){
          ans = "Weird";
        }
        elseif(n%2==0 && 2<=n<=5)
        {
        ans = "Not Weird";
        }
        elseif(n%2==0 && 6<=n<=20)
        {
            ans = "Weird";
        }
        elseif(n%2==0 && n>20)
        {
            ans = "Not Weird";
        }
        System.out.println(ans);

    }
}

It shows compilation error of semicolon after elseif statement.