Cannot find symbol, using Scanner and Switch Cases

Question

Converting letters (A-F and any others should say error) into binary using a switch case this is the main:

Scanner keyboard = new Scanner(System.in);
System.out.println("Enter a letter :: ");
String letter = keyboard.next();
keyboard.getBinary();
keyboard.toString();

and the class:

import static java.lang.System.*; 
public class HexToBinary
{
private char hex;

public HexToBinary()
{
    hex=0;
}

public HexToBinary(char hexNum)
{

    hex=hexNum;
}

public void setHex(char hexNum)
{
    hex=hexNum;
}

public String getBinary()
{
    String letter = letter;
    switch(letter)
    {
        case A: letter = 1010;
        case B: letter = 1011;
        case C: letter = 1100;
        case D: letter = 1101;
        case E: letter = 1110;
        case F: letter = 1111;
        case default: letter = ERROR;
    }
    return "";
}

public String toString()
{
    System.out.println(letter+" is " getBinary + "in binary!")
    return "";
}

the error says it cannot find symbol at the period of "keyboard.getBinary();" not sure what the problem is

Answer 1

the error says it cannot find symbol at the period of "keyboard.getBinary();" not sure what the problem is

Scanner doesn't have a getBinary() method as the API will tell you: Scanner API.

More importantly
But your HexToBinary class does have this method. You will want to create a HexToBinary variable, assign it a HexToBinary object, and then call this method on this variable.

So not:

Scanner keyboard = new Scanner(System.in);
System.out.println("Enter a letter :: ");
String letter = keyboard.next();
keyboard.getBinary();
keyboard.toString();

but rather:

Scanner keyboard = new Scanner(System.in);
System.out.println("Enter a letter :: ");
String letter = keyboard.next();

// check that letter has only one char in it.
// convert your letter to a char. 
// create a HexToBinary variable and object here
// use its methods to convert the char to binary.