javascript function definition and calling syntax

js_fn_def_and_calling.js

// this is function definition.
// you can make a function take zero or more arguments (also called as parameters)
// This Dog fn takes one argument: 'name'
function Dog(name){
  return "hello, my name is: " + name;
}

// calling the Dog function
Dog('tommy');  // this will return "hello, my name is: tommy"

// you can check this in chrome js console with:
console.log(Dog('tommy'));

////////////////////////////////////////

//// Objects

var person = {}; // an empty object. We can add anything to it later on like below

// you can add 'attribute' properties to an object
person.age = 28;
person.name = 'prasanna';

// you can check the value of 'person' now
console.log(person);  // you should see something like: {age: 28, name: 'prasanna'}

// you can also add 'function' properties to an object

// let's teach our person object to say his name
person.sayName = function() {
  return "My name: " + this.name;  // notice the use of 'this'
};

// you can now ask the person object to say his name!
console.log( person.sayName() );  // "My name: prasanna" will be the output