Primitive Data Types
These are my notes on primitive data types in Java.
Notes on Primitive Data Types
There are two main types of data structures, primitive and non-primitive. Strings, arrays, etc. are examples of non-primitive data types.
Within primitive data types, we have boolean, characters (chars), bytes, shorts, ints, longs, floats, and doubles. For non-primitive data types, it is anything the is, well, non-primitive. For example, we have arrays and strings.
// java style to import library
import java.util.Scanner;
public class TestPrimitives {
public static void main(String[] args) {
Scanner input;
// Integers
input = new Scanner(System.in);
System.out.print("Enter an integer: ");
try {
int sampleInputInt = input.nextInt();
System.out.println(sampleInputInt);
} catch (Exception e) { // if not an integer
System.out.println("Not an integer, " + e);
}
input.close();
// Doubles
input = new Scanner(System.in);
System.out.print("Enter a double: ");
try {
double sampleInputDouble = input.nextDouble();
System.out.println(sampleInputDouble);
} catch (Exception e) { // if not a number
System.out.println("Not an double, " + e);
}
input.close();
// Booleans
input = new Scanner(System.in);
System.out.print("Enter a boolean: ");
try {
boolean sampleInputBoolean = input.nextBoolean();
System.out.println(sampleInputBoolean);
} catch (Exception e) { // if not true or false
System.out.println("Not an boolean, " + e);
}
input.close();
// Wrapper Class Strings
input = new Scanner(System.in);
System.out.print("Enter a String: ");
try {
String sampleInputString = input.nextLine();
System.out.println(sampleInputString);
} catch (Exception e) { // this may never happen
System.out.println("Not an String, " + e);
}
input.close();
}
}
TestPrimitives.main(null);