Node.Js

Questão	Responda
What is the primary feature of Node's build model?	Node works on a model of asynchronous, non-blocking input and output.
What is the concept of asychronicity?	In Node, asynchronicity refers to the fact that the server will not block progress through the program, rather it will call the next function while waiting for it's current function to complete.
Does Node support multiple threads?	No, node is a single-thread model. That being said, its non-blocking nature allows a single thread to operate quicker and more smoothly than many traditional multi-thread model servers, such as with the LAMP stack.
How does Node handle media buffering?	Node does not buffer data, rather providing it in chunks as soon as they are available.
Why use Node rather than a traditional model like the LAMP stack?	Node is simple to use, easy to read and edit, and most importantly is designed to handle applications with heavy server interactions, such as high traffic and data-heavy operations.
What is the method for including an installed Node module in a working file?	To do this, one must create a variable, give it a name and assign its value as the function require("module-name")
What is a callback?	Callbacks are similar to functions in most programming languages, but are non-blocking by design. They are based on a concept of request and response. When a request is made, the callback performs its operations while the server continues down the list of remaining callbacks, then sends out its response when it's ready.
What is the difference between an event and a callback?	Callback functions are called when an asynchronous function returns its result, whereas event handling works on the observer pattern, and executes when an event is fired.
What is the basic syntax for binding an event handler?	eventEmmitter.on('event', eventHandler)
What is a Node Buffer Object?	Node uses the Buffer class to create object instances allowing it to interact well with binary data. This is essential for Node to communicate with TCP and file systems.
How do Buffer Objects work?	Buffer objects contain data in octets representing bytes. Node is a UNICODE based language, and requires this object class to properly parse binary data.
How does one 'stringify' the encoded octets of a Buffer object?	.toString(encoding [, start][, end])
Can a Buffer object be parsed into JSON?	Yes, there is a simple method following the syntax Buffer.toJSON() that will populate a JSON doc with binary octet bytes representing the working Buffer object.
What are the main strategies for state management in Node?	The best way to handle states, is by passing a local variable directly to the state-dependent function, or by acquiring a variable from cache, session, a file, a database, network, or other outside source. Global variable use should be avoided as much as possible.
Is it possible to iterate through objects in Node?	As long as the object is available in memory, yes. Otherwise, there will be an error in the execution and return order for the callback.
What are the 3 features intended to help ensure that callback nesting is handled cleanly and asynchronously?	Promises, Async and Await
When will process.nextTick() execute?	process.nextTick() will run at the end of the event loop, before the next loop starts.
What is the best method for handling cascading functions that may overlap in processing time?	To avoid overlapping processing for cascading functions, use recursive timeout, this will cause a delay between the end of the initial function and begining the execution of the next.
What is the purpose of setImmediate()?	When you want to execute some piece of code asynchronously, but as soon as possible. Any function passed as the setImmediate() argument is a callback that's executed in the next iteration of the event loop.
What is the order of queue execution in Node?	The process.nextTick queue comes first, then the promises.next microtask queue followed by the macrotask queue.

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	Criado por Kyle Peters mais de 1 ano atrás