Presentation given to my coworkers at Policia Militar da Paraíba. It is just a introduction to Javascript language and what it is made for.

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