Thread: java program that converts number grades to letter grade

I wrote a java application that coverts number grades to letter grades. Here is what it looks like:

/java application to That corresponds the letter grade with the number grade
 
import java.util.Scanner; //program uses the class scanner
 
public class gradescore{
 
 
//main method begins execution of java application
 
public static void main(String args[]){
	Scanner input=new Scanner(System.in);
 
	int grade;
 
	System.out.printf("Entered the numbered grade you received");
	grade=input.nextInt();
 
	if(70>=grade>=60)
	   System.out.println("Your grade is a D"); //java code tells you that your letter grade is a D if you input a score that is between  60 and 70
	if(80>=grade>=70)
	   System.out.println("You received a C letter grade");//java code tells you that your letter grade is a C if you input a score that is between and includes 70 and 80
	if(90>=grade>=80)
	   System.out.println("You received a B letter grade");//java code tells you that your letter grade is a B if you input a score that is between and includes 90 and 80
	if(100>=grade>=90)
	   System.out.println("You received an A letter grade");//java code tells you that your letter grade is a A if you input a score that is between and includes 100 and 90
	if(60>grade)
	   System.out.println("You received an F letter grade"); //java code tells you that your letter grade is an F is you input a score that is below 60
 
 
 
 
 
}//end method
}//end class gradescore

Here are the errors that are displayed with I attempt to compile the code.

C:\Users\Courtney\Desktop\gradescore.java:31: error: '(' expected
if
^
C:\Users\Courtney\Desktop\gradescore.java:33: error: illegal start of expression
}//end method
^
C:\Users\Courtney\Desktop\gradescore.java:33: error: ')' expected
}//end method
^
C:\Users\Courtney\Desktop\gradescore.java:35: error: illegal start of statement
C:\Users\Courtney\Desktop\gradescore.java:34: error: reached end of file while parsing
}//end class gradescore
^
5 errors

Tool completed with exit code 1

What is wrong with my code?

Your if() statements are not valid. For example:

if(70>=grade>=60)

is two conditions written as one:

grade <= 70, and
grade >= 60

The two conditions must be written separately and combined with an AND (&&):

if ( grade >= 60 && grade <= 70 )

There are several considerations to be made here.

First, why such long comments on lines that are already printing output? Comments are tools used to point out important logic and reasoning in a program to other programmers - you should assume someone reading your comments knows what an import and a method declaration are. You should comment "why" the code is doing something, rather than "what" it is doing, or the comment will simply be redundant.

Second, stick to the Java convention of enclosing blocks with curly brackets {}.

Third, use the else operator. Even if your logic was correct (refer to the above posts), you're performing unnecessary checks -

if (grade >= 90) {
  System.out.println("You received an A");
} else if (grade >= 80) {
  System.out.println("You received a B");
} else if (grade >= 70) {
  System.out.println("You received a C");
} else if (grade >= 60) {
  System.out.println("You received a D");
} else {
  System.out.println("You received an F");
}

is sufficient.