\nMessage passing for communication between objects<\/em><\/p>\n<\/blockquote>\n\n\n\nIn programming a object<\/strong> It is a digital form of group features<\/strong> and that some of them may be analogous to an object in real life, but that it is much more limited and should not be expected to be the same, because it is only a digital representation<\/strong>.<\/p>\n\n\n\nWhen you develop software, and you need to add functionality, modify or fix a bug, your logical thinking is based on representation of digital objects, their relationships and communications with other digital entities<\/strong>. You should never think that as the real object behaves in a certain way, so does its representation. It is very helpful conceptually, but in implementation they are very often different.<\/p>\n\n\n\nLet's remember what Alan Kay tells us:<\/p>\n\n\n\n
\nI'm sorry I coined the term a long time ago. Objects<\/strong> for programming because it made people focus on the least important part. The big idea is "Sending messages<\/strong>\u00ab<\/p>\nAlan Kay<\/cite><\/blockquote>\n\n\n\nAlso a object<\/strong> serves for store data<\/strong> useful that other objects can use. So an object serves us to:<\/p>\n\n\n\n\nCreate communications between digital representations of objects<\/strong>.<\/li>\n\n\n\nIt allows grouping functionalities related to the digital representation of the object.<\/li>\n\n\n\n Stores data that another object can use. (It works like some data structures.)<\/li>\n<\/ul>\n\n\n\nWhat are objects in Node.js and JavaScript?<\/h2>\n\n\n\n The objects<\/strong> in Node.js and Javascript, they are a collection of pairs name: value<\/code>, similar to PHP's "associative arrays." These pairs of name\/value<\/code> They are called properties, a property is like a variable and can contain any type of value.<\/p>\n\n\n\nThe key to the previous paragraph is that it can contain any type of value, including functions. And with this two types of objects are identified.<\/p>\n\n\n\n
\nObjects with functionalities and communications<\/strong>\n\nWhich for the most part have methods to communicate with other objects<\/strong> and solve problems.<\/li>\n<\/ol>\n<\/li>\n\n\n\nObjects with data<\/strong>. Also called data structure\n\nWhich for the most part contains data and which helps us to store and send information<\/strong> through messages. These objects are used by objects with functionalities and communications.<\/li>\n<\/ol>\n<\/li>\n<\/ol>\n\n\n\nLet's remember that everything related to objects also works anywhere JavaScript is executed, node.js<\/strong> including.<\/p>\n\n\n\nHow to create objects in Node.js and Javascript?<\/h2>\n\n\n\n The simplest way to create an object is through an object literal. A literal object is one that is created with curly braces {}<\/code>, adding its properties and methods. Like the following example.<\/p>\n\n\n\n<\/circle><\/circle><\/circle><\/g><\/svg><\/span><\/path><\/path><\/svg><\/span>const<\/span> James <\/span>=<\/span> <\/span>{<\/span><\/span>\n <\/span>name<\/span>:<\/span> <\/span>'<\/span>Jaime<\/span>'<\/span>,<\/span><\/span>\n <\/span>last name<\/span>:<\/span> <\/span>'<\/span>Cervantes<\/span>'<\/span>,<\/span><\/span>\n <\/span>mother's last name<\/span>:<\/span> <\/span>'<\/span>Velasco<\/span>'<\/span>,<\/span><\/span>\n <\/span>edad<\/span>:<\/span> <\/span>33<\/span>,<\/span><\/span>\n <\/span>getName<\/span>:<\/span> <\/span>functions<\/span> <\/span>()<\/span> <\/span>{<\/span><\/span>\n <\/span>return<\/span> <\/span>'<\/span>Jaime Cervantes Velasco<\/span>'<\/span>;<\/span><\/span>\n <\/span>}<\/span><\/span>\n};<\/span><\/span>\nJames<\/span>.<\/span>getName<\/span>()<\/span>;<\/span> <\/span>\/\/ Jaime Cervantes Velasco<\/span><\/span><\/code><\/pre><\/div>\n\n\n\nWe have an object with five properties, name<\/code>, last name<\/code> and mother's last name<\/code> are of type string, age<\/code> is type number<\/code> and the last property, getName()<\/code> is type functions<\/code>. Here you have more information about data types<\/a>.<\/p>\n\n\n\nAlthough we will see the functions in detail later, for now, we can say that the functions allow us to encapsulate and execute a set of operations that we do very often. Instead of repeating the code of these operations many times, we better put these operations inside a function.<\/p>\n\n\n\n
Whenever we need to execute these operations, we simply execute the function, this execution of the function is called invocation<\/strong>. Example of invocation is in the last line, where we use parentheses, jaime.getName();<\/code>.<\/p>\n\n\n\nHow do I get the value of a property?<\/h2>\n\n\n\n To obtain some property of an object, we can do it in two ways:<\/p>\n\n\n\n
\nDot notation<\/li>\n\n\n\n Using square brackets, much like accessing data in a array<\/code><\/li>\n<\/ul>\n\n\n\nThe first way, dot notation, is very simple, example:<\/p>\n\n\n\n
<\/circle><\/circle><\/circle><\/g><\/svg><\/span><\/path><\/path><\/svg><\/span>const<\/span> James <\/span>=<\/span> <\/span>{<\/span><\/span>\n <\/span>name<\/span>:<\/span> <\/span>'<\/span>Jaime<\/span>'<\/span>,<\/span><\/span>\n <\/span>last name<\/span>:<\/span> <\/span>'<\/span>Cervantes<\/span>'<\/span>,<\/span><\/span>\n <\/span>mother's last name<\/span>:<\/span> <\/span>'<\/span>Velasco<\/span>'<\/span>,<\/span><\/span>\n <\/span>edad<\/span>:<\/span> <\/span>33<\/span>,<\/span><\/span>\n <\/span>getName<\/span>:<\/span> <\/span>functions<\/span> <\/span>()<\/span> <\/span>{<\/span><\/span>\n <\/span>return<\/span> <\/span>'<\/span>Jaime Cervantes Velasco<\/span>'<\/span>;<\/span><\/span>\n <\/span>}<\/span><\/span>\n};<\/span><\/span>\nJames<\/span>.<\/span>name <\/span>\/\/ 'Jaime'<\/span><\/span>\nJames<\/span>.<\/span>last name<\/span>;<\/span> <\/span>\/\/ 'Cervantes'<\/span><\/span>\nJames<\/span>.<\/span>mother's last name<\/span>;<\/span> <\/span>\/\/ 'Velasco'<\/span><\/span>\nJames<\/span>.<\/span>edad<\/span>;<\/span> <\/span>\/\/ 33<\/span><\/span>\nJames<\/span>.<\/span>getName <\/span>\/\/ function () { return 'Jaime Cervantes Velasco'; }<\/span><\/span><\/code><\/pre><\/div>\n\n\n\nThe second way, using square brackets []<\/code>, example:<\/p>\n\n\n\n