使用scanner类输入数组（错误：不兼容类型：扫描程序无法转换为String）

Question

I'm trying to input student details using a scanner but I keep getting this error:

error: incompatible types: Scanner cannot be converted to String

I have 4 scanners which are

static Scanner name = new Scanner(System.in);
static Scanner Date = new Scanner(System.in);
static Scanner address = new Scanner(System.in);
static Scanner gender = new Scanner(System.in);

My code is as follows

System.out.println("You have chosen to add a student. Please enter the following details");
System.out.println("Name: ");
String Name = name.nextLine();  
System.out.println("DOB: ");
String DOB = Date.nextLine();
System.out.println("Address: ");
String Address = address.nextLine();
System.out.println("Gender: ");
String Gender = gender.nextLine();

app.addStudent(name, DOB, address, gender);
System.out.println(Name + " has been added!" + "\n" + "Returning to menu....");

app.delay();

The addStudent method is as follows

public void addStudent (String name,String DOB,String address,String gender)
{
    for(int i = 0; i < enrolment.length; i++)
    {
        if (enrolment[i] == null)
        {
            this.enrolment[size] = new Student(name, DOB, address, gender);
            this.size++;

            if (gender == "Male")
            { 
                this.maleStudents++;
            }
            else { 
                this.femaleStudents++; 
            }
            break;
        }
    }
}

Answer 1

The problem is that you're passing your Scanner objects to your addStudent method instead of the strings that you obtained from the scanners:

app.addStudent(name, DOB, address, gender);

Should be

app.addStudent(Name, DOB, Address, Gender);

Also:

• one Scanner object should be sufficient. No need for four of them.
• Java code conventions dictate that variable names are in lower camel-case, ie gender instead of Gender .

---

Putting everything together, your code should look something like this:

Scanner scanner = new Scanner(System.in);

System.out.println("You have chosen to add a student. Please enter the following details");

System.out.println("Name: ");
String name = scanner.nextLine();

System.out.println("DOB: ");
String dob = scanner.nextLine();

System.out.println("Address: ");
String address = scanner.nextLine();

System.out.println("Gender: ");
String gender = scanner.nextLine();

app.addStudent(name, dob, address, gender);

System.out.println(name + " has been added!" + "\n" + "Returning to menu....");

Answer 2

You only need one scanner, not one for each input.

In you code you are confusing Name (the string) with name (the scanner).

This is why there are naming rules.

Try changing to

 Scanner input = new Scanner (System.in);

 String name = input.nextLine ();
 String gender = input.nextLine (); 
 ...

then

 app.addStudent (name, dob, address, gender);

try also reading about naming conventions

Answer 3

name, adress, and gender are scanners, your method takes Strings

app.addStudent(Name, DOB, Address, Gender);

is the method with the String variables that you defined