2 Elements and Data Types

Most Important Concepts / Code

Pseudocode is an informal language that has no syntax rules and is not meant to be compiled or executed.

A flowchart is a diagram that graphically depicts the steps that take place in a program.= is the assignment operator. It is read "is assigned" or "gets", not "equals".

A variable is a location in memory.

Name variables as descriptive nouns using camelCase.

Java has 8 primitive data types: byte, short, int, long, float, double, boolean, char.

System.out.println("Hello World!"); // basic output

int num1; // variable declaration, once and only once

num1 = 5; // assignment, can be reassigned

int gear = 1; // declaration + assignment = initialization

Getting Input Preview:

Create a Scanner object, like Scanner scanner = new Scanner(System.in);

System.out.println("Enter x1"); // prompt

int x1 = scanner.nextInt(); // get int input, will crash if input isn't an int

double rate = scanner.nextDouble(); // get double input, will crash if input isn't a number

// when going from reading numbers to reading strings you could have a problem because nextInt and nextDouble don't consume the Enter keystroke

scanner.nextLine(); // Consume left-over newline

String firstName = scanner.next(); // reads input until a space

String address = scanner.nextLine(); // reads input including spaces until the end of line \n

if Statement Preview:

If else statements look like this

if (condition) {

something that only happens when condition is true

} else {

something that only happens when condition is false

}