**Apologies about this being a two-part video, AND for my mic volume being weird, in future videos this is fixed. I’ll consider re-recording this later**

Topics Discussed: Using math functions with if-based logic to choose the output of a program

Source code for Lesson 8, Part 1:

import java.lang.Math; import java.util.Scanner; class Jtutorial1 { public static void main(String args[]){ Scanner input = new Scanner(System.in); // Declare a double, run some tests on it. // Is it even or odd? Is it a perfect square? Is it a whole number? // Is the number squared even? double choice=0; System.out.println("Enter a value for the variable: "); choice = input.nextDouble(); //even if((choice%2) < 1){ System.out.println("The number " + choice + " is even prior to the decimal point. "); } else{ System.out.println("The number " + choice + " is NOT even. "); } //perfect square if((Math.sqrt(choice)) == 0){ System.out.println("The number " + choice + " is a perfect square: "); } else{ System.out.println("The number " + choice + " is NOT a perfect square: "); } if ((choice%1) == 0){ System.out.println("The number " + choice + " is a whole number: "); } else { System.out.println("The number " + choice + " is NOT a whole number: "); } if((((Math.pow(choice, 2)))%2) == 0){ System.out.println("The number " + choice + " squared is even: "); } else{ System.out.println("The number " + choice + " squared is NOT even: "); } } //End main } //End class

**8-2 Here**

Topics discussed: Same as above

Source Code for Lesson 8, Part 2:

import java.lang.Math; import java.util.Scanner; class Jtutorial1 { public static void main(String args[]){ Scanner input = new Scanner(System.in); // Declare a double, run some tests on it. // Is it even or odd? Is it a perfect square? Is it a whole number? // Is the number squared even? double choice=0; System.out.println("Enter a value for the variable: "); choice = input.nextDouble(); //even if((choice%2) < 1){ System.out.println("The number " + choice + " is even prior to the decimal point. "); } else{ System.out.println("The number " + choice + " is NOT even. "); } //perfect square if(((Math.sqrt(choice))%1) == 0){//sqrt(9) == 3 System.out.println("The number " + choice + " is a perfect square: " + Math.sqrt(choice)); } else{ System.out.println("The number " + choice + " is NOT a perfect square: " + Math.sqrt(choice)); } if ((choice%1) == 0){ System.out.println("The number " + choice + " is a whole number: "); } else { System.out.println("The number " + choice + " is NOT a whole number: "); } if((((Math.pow(choice, 2)))%2) == 0){ System.out.println("The number " + choice + " squared is even: "+ Math.pow(choice, 2)); } else{ System.out.println("The number " + choice + " squared is NOT even: " + Math.pow(choice, 2)); } } //End main } //End class

In these videos I talk a little bit about java.lang.Math; An include that allows us to do some simple mathematical calculations in our code in conjunction with the if-statements we’ve been talking about.

**java.lang.Math functions**

There are a LOT of different constructs in the java.lang.Math library, but the ones we use in this lesson seem to be the most common of them. Raising a number to a power, and taking the square root of a number. The code for each of these is as follows: (assuming you have the import in your code)

Examples:

Math.pow(numberOrVariable, powerRaisingTo); Math.pow(x, 3); // raises x to the 3rd power Math.sqrt(x); // Gets the square root of X