Primitive Data Types Hacks • 5 min read

Sep 11, 2023

Description

Primitive Data Type Hacks

Demonstration of:

Integers
Boolean
Double

import java.util.Random;
import java.util.Scanner;

int guess; // initialize user guess

Random rand = new Random(); // create new random object
Scanner scan = new Scanner(System.in);

int random_integer = rand.nextInt(20); // create random number
int[] guesses = {0,0,0,0,0}; // create guesses (preset to 5 because that is how many guesses there are)

System.out.println(random_integer);

for(int i = 0; i < guesses.length; i++){
    System.out.println("Guess a number");
    guess = scan.nextInt();
    if (guess > random_integer){
        System.out.println("Your guess is higher!");
    }  
    else if (guess < random_integer){
        System.out.println("Your guess is lower");
    } 
    else {
        System.out.println("You got it! The number was " + random_integer);
        guesses[i] = guess;
        break;
    }
    guesses[i] = guess;
}

System.out.println("Calculating mean of all data...");

int mean = 0;
for (int i : guesses){
    mean += i;
}

double do_mean = mean/5f;
System.out.println("Mean is " + do_mean);

9
Guess a number
Your guess is lower
Guess a number
Your guess is lower
Guess a number
You got it! The number was 9
Calculating mean of all data...
Mean is 3.799999952316284

Type Casting Examples

Wide casting: You take a data type that has a lower bit storage amount and cast it into a higher bit storage amount
Narrow casting: The opposite of wide casting; take a larger data type and cast it into a smaller amount.

Wide casting can be done automatically, while narrow casting must be manual.

Wide Casting

// Wide casting

int my_int = 1241;

System.out.println(my_int);

double my_doub = my_int; // widening my_int from an integer to a double (32 --> 64 bit)

System.out.println(my_doub); // Prints with a floating point numbera

1241
1241.0

Narrow Casting

double my_doub = 12.2421; // initialize a double (64 bit number)

System.out.println(my_doub); // define double with float

System.out.println((int) my_doub); // Prints with a truncated decimal (32 bit integer number)

// Manually Casting Wider:
int new_int = 12;
System.out.println((double) new_int); // Manually cast wider using double