Java Intro Tutorial Part 1

alert('hello world');
console.error('this is an error');
console.warn('this is a warning');
console.log('Hello world');

// Variables: var, let and, const.  Mainly use let and const
// as var is a global variable

let age = 30;
 age = 35;
console.log('My age is ' + age);

// Use const unless you know you'll be reassigning something, like a score.

//Data Types: Strings, numbers, boolean, null, undefined, symbol

const name = 'Jason';
const myAge = 41;
const isCool = true;
const rating = 4.5;
const x = null; // this means it's empty, a variable with nothing in it
const y = undefined;
let z; //this is also undefined.

console.log(typeof name);
console.log(typeof myAge);
console.log(typeof isCool);
console.log(typeof rating);
console.log(typeof x);
console.log(typeof y);
console.log(typeof z);

//Concatenation
console.log('My name is ' + name + ' and I am ' + age);

//Template... uses backticks, not single quotes
const hello = (`My name is ${name} and I am ${age}`);
console.log(hello);

const s = 'Hello World!';
console.log(s.length);
console.log(s.toUpperCase()); //makes s uppercase
console.log(s.toLowerCase());
console.log(s.substring(0,5).toUpperCase()); // only prints first five letters

const t = 'tech, computers, it, code'
console.log(t.split(', ')); //splits t into an array