Thread: Trying to learn and I'm stuck

Hey everyone, I am very new to Java programming and I'm stuck!

I'm working through a book that sets me exercises etc but I wondered if you could tell me what I'm doing wrong here.

Im trying to add a conditional statement to my constructor, that counts the amount of characters in a string and prints an error message if the string has less than 4 characters.

I know the String class has a length accessor method, and thats what I'm trying to use here.

public class Student
{
    // the student's full name
    private String name;
    // the student ID
    private String id;
    // the amount of credits for study taken so far
    private int credits;
 
    /**
     * Create a new student with a given name and ID number.
     */
    public Student(String fullName, String studentID)
    {
        name = fullName;
        id = studentID;
        credits = 0;
 
 
        if(studentID.length < 4)
        {
            System.out.println("You need 4 or more charaters");
        }
    }

Now this just doesn't compile, it has a problem with .length in my if statement.

It's not obvious why this won't work, could someone please help me out?

Thanks!

Length is a method, not a field. the correct way to get the length of studentID is studentID.length() not studentID.length

You can look at the String documentation here: String (Java Platform SE 6)

HA! thanks.. I was just being dumb then.