The document serves as a basic introduction to JavaScript, covering fundamental types such as numbers, strings, and booleans, as well as variable declaration and operations. It explains concepts like data coercion, logical operators, and control structures including loops and functions. Additionally, it presents challenges for implementing functions to calculate powers and create a chess grid.

1. JAVASCRIPT
THE BASICS
Created by /Bruno Paulino @brunojppb

2. BASIC TYPES
Number
String
Boolean
Object
Function
Undefined

3. VARIABLE DECLARATION
var num = 10; //number
var str = "hello, there"; //string
var bool = true; //boolean
var foo = { //object
name: 'Bar'
};
var bark = function() { //function
console.log('Ruff!');
};

4. OPERATIONS
Unary
console.log(typeof 23.0);
// number
Binary
if(102 > 101) {
console.log('greater than');
}
// greater than
Ternary
var discount = 10 > 12 ? "10% OFF" : "20% OFF";
console.log("Code: " + discount);
// Code: 20% OFF

5. OPERATORS
Logical
|| && == != === !===
Arithmetic
* / - + %

6. "==" AND "===" ARE NOT THE SAME
if("5" == 5) {
console.log("Same thing.");
}
// Same Thing.
if("5" === 5) {
console.log("same thing.");
} else {
console.log("Ops! This is not the same thing.");
}
// Ops! They are not the same thing.
WHY?
Data coercion
“Javascript will quietly convert that value
to the type it wants, using a set of rules
that often aren’t what you want or expect.”
Eloquent Javasctipt

7. SHORT-CIRCUITING
console.log(null || 'Foo');
// Foo
console.log('Foo' || 'Bar');
// Foo
console.log('Bruno' && 0);
// 0
console.log(false && 0);
// false

8. LOOP
for(var i = 0; i < 5; i++) {
console.log("i: " + i);
}
// 5 times: "i: n"
var counter = 0;
while(counter < 5) {
console.log('counter: ' + counter);
counter++;
}
// 5 times: "counter: n"
var newCounter = 0;
do {
console.log('newCounter: ' + newCounter);
newCounter++;
}while(newCounter < 5);
// 5 times: "counter: n"

9. FUNCTIONS
function sayHello() {
console.log('Hello!');
}
var sayHiTo = function(name) {
console.log('Hi ' + name);
}
sayHello();
sayHiTo("Bruno");

10. OPTIONAL ARGUMENTS
var sayHello = function(name) {
if (name == undefined)
console.log('Hello! There!');
else
console.log('Hello! ' + name + "!");
}
sayHello();
// Hello! There!
sayHello("bruno");
// Hello! Bruno!

11. CHALLENGE 1
Write a function that calculates the power of a number. The
first argument is required(the base) and the second should
be optional(the exponent), which is 2 by default.
Solution

12. CHALLENGE 2
Write a function that creates a chess grid dinamically with a
space and a hashtag(#). The function should receive 2
arguments. The first one is the width, the second one is the
height of the grid. The output should look like this for a 8x4
chess grid:
// call function
createChess(8, 4);
//output:
/*
# # # #
# # # #
# # # #
# # # #
*/
Solution

13. THANK YOU
REFERENCES:
Eloquent Javascript
Professional Javascript for web developers