User Input

Tags

Java OOP Public

Difficulty

Easy

Expected time

15min

Author

User interface contains two types of user input controls: TextInput, which accepts all characters and NumericInput, which accepts only digits.

Implement the class TextInput that contains:

Public method void add(char c) - adds the given character to the current value
Public method String getValue() - returns the current value

Implement the class NumericInput that:

Inherits from TextInput
Overrides the add method so that each non-numeric character is ignored

For example, the following code should output "10":

TextInput input = new NumericInput();
input.add('1');
input.add('a');
input.add('0');
System.out.println(input.getValue());

Java SE 8

Show starting code

public class UserInput {
    
    public static class TextInput {}

    public static class NumericInput {}

    public static void main(String[] args) {
        //TextInput input = new NumericInput();
        //input.add('1');
        //input.add('a');
        //input.add('0');
        //System.out.println(input.getValue());
    }
}

Example case: java.lang.ClassCastException
Adding various characters to TextInput: java.lang.NoSuchMethodException
Adding numeric characters to NumericInput: java.lang.ClassCastException
Adding various characters to NumericInput: java.lang.ClassCastException