Asynchronous Programming - Reading Assignment

Javascript Programming
#882

1. What is the difference between synchronous and asynchronous functions?
A synchronous function is linear. Whereas an asynchronous function is non-linear starting and complete at a later time.

2. What is callback hell?
Callback hell is a loop of executing multiple asynchronous operations.

3. Which technique can help us solve callback hell?
Using JS Node Promises is a standardized way to mitigate callback hell.

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#883
  1. sync: block executing by waiting for task to complete
    async: start a task wait for an event, notifying that the task has been executed
  2. when you have nested async fx calls and therefore code becomes very complicated to read
  3. chain the callbacks, sync style code.
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#884

  1. Synchronous functions are single-threaded so that they can only handle one event at a time. They have to wait for the full completion of the first task to start on the second task. Asynchronous functions are multi-threaded and can simultaneously handle several events. It achieves this by responding to callbacks.

  2. When you use too many callbacks in extensive code the complexity of the code quickly makes it unmanageable. This is known as callback hell.

  3. In the browser you can use the jQuery feature of “promises” that helps you chain callbacks and deal with errors. In Node.js you can abstract away the asynchronicity by using the Fibers package.

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#885

  1. A synchronous function occur one after the other and don’t allow the next function to begin executing until its completion (it is single-threaded), whereas an asynchronous function will allow other functions to begin before it has completed all of its tasks ( it can be initiated and then put aside until a later date while the thread gets started on the next task on the event loop).

  2. Callback hell is a situation where several functions are being performed in nested form
    (excessive number of callbacks nested within one another, making the code overly complex to manage and messy /difficult to read).

  3. Promises allow us to chain callbacks and deal with errors (help make the code easier to read and manage).

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#886
  1. synchronous functions in a linear way, where one function must finish before the next, where an asynchronous function can function multiple calls at once when one or more calls or functions are not yet finished.
  2. callback hell is where function calls stack up as they go unanswered/unfinished.
  3. code that uses promises can be easier to manage
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#887
  1. Synchronous functions can block any additional functions still the first one finish. Meanwhile asynchronous functions can start a program an move on to run another block of code.
  2. Callback hell is when many asynchronous functions are nested waiting to another function to finish execution.
  3. We can use promise libraries to solve it. jQuery comes with a build-in promise libraries and in Node.js we can use Meteor.
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#888
  1. Synchronous code executes in sequence, there is a wait time each statement has wait for the previous statement to finish. Asynchronous code doesn’t have to wait, code can continuous to run.
  2. Callback hell is when we experience many multiple line of nested function codes and have no way to handle code in simple way.
  3. In JavaScript, we can use Promise technique to help solve with the come back hell problems.
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#889

  1. Synchronous functions cannot start next task (piece of code) until one is finished asynchronous may neglect, or leave for later some parts of codes to run it later

  2. Callback hell occurs when one function initiate callback of another function that calls another function and so on…

  3. Promises can help us to solve callbackhell

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#890
  1. Synchronous functions must happen one after the other, and each next function can’t start until the previous one is complete. Asynchronous functions can be initiated and put aside to be completed at a later time, so that more important immediate tasks can be completed first.
  2. When several asynchronous functions are nested to complete an operation.
  3. Promises can be used to overcome callback hell. jQuery ships with a built-in promise library - this allows developers to chain callbacks and deal with errors. You can also use Node.js to extend the runtime.
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#891
  1. Synchronous functions work one after another.One action starts and has to finish so that the next action can start. Asynchronous functions might start and while waiting for replies the next function can be executed. For example the you are building a house and you have ordered windows you don’t have to wait until they come instead you order them and while waiting for them you build the roof.
  2. Callback hell is a poetical description of a program or even the whole document which has to many nested functions. It gives our engine too many callbacks.
  3. In Javascript we can use promises for example via jquery promise libraries, in Node.js you can extend the runtime to make the code look synchronous instead asynchrone. The mentioned Meteor uses Fibers package for this.
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#892

What is the difference between synchronous and asynchronous functions?

  • asynchronous code usually takes the form of Ajax. Ajax is most commonly used through a jQuery wrapper. The asynchronous task can be initiated and then put aside until a later date while it gets started on the next task on his to-do list
  • With JavaScript’s single-threaded nature, synchronous code will lock up the browser for the duration of its execution

What is callback hell?

  • In more complex operations, tendency to produce even more levels and sub-levels is callback hell

Which technique can help us solve callback hell?
-a common pattern to deal with excessive callbacks is to use promises

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#893

  1. What is the difference between synchronous and asynchronous functions? A synchronous task will occupy Javascript continuously
    until its completion, an asynchronous task can be initiated in JS and then put aside until a later date.

  2. What is callback hell? When a relatively simple operation that requires more complex operations produces even more levels and sub-levels of code.

  3. Which technique can help us solve callback hell? Promises

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#894

1. What is the difference between synchronous and asynchronous functions?

Synchronous functions in JS are functions that execute one after the other. Hence, each successive function will not execute unless the one before it has finished execution.

Asynchronous functions , such as callbacks, typically use the event loop, and can start execution but don’t lock up the browser until they’re finished. In contrast, other code below the functions continues executing until the task being done by the asynchronous function finishes execution.

2. What is callback hell?

Callback hell is when multiple asynchronous functions become nested, one within the other, each designed to be executed after a certain asynchronous task (file read being complete, ajax request completion, etc.) has finished.

3. Which technique can help us solve callback hell?
JS promises and the new async, await key words are one two ways to avoid callback hell.

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#895

What is the difference between synchronous and asynchronous functions? In synchronous operations tasks are performed one at a time and only when one is completed, the following is unblocked. In other words, you need to wait for a task to finish to move to the next one. In asynchronous operations, on the other hand, you can move to another task before the previous one finishes.

What is callback hell? This is a big issue caused by coding with complex nested callbacks . Here, each and every callback takes an argument that is a result of the previous callbacks. In this manner, The code structure looks like a pyramid, making it difficult to read and maintain.

Which technique can help us solve callback hell? In the browser, a common pattern to deal with excessive callbacks is to use promises. jQuery ships with a simple built-in promise library that enables us to chain callbacks and deal with errors

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#896

  1. Synchronous functions are functions that run in chronological order, meaning that only one function can run at any one time. Whereas, asynchronous functions are functions that do not follow a specific order. This means that several functions can run at the same time. We can think of Async. functions as functions that allow our app to multitask.

  2. Callback hell refers to a situation where several functions are nested within each order. This means that functions have other functions within them and this situation can become very undesirable when programming.

  3. Promises can be used to solve callback hell and different libraries come with promise functionalities to help solve callback hell.

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#897

  1. What is the difference between synchronous and asynchronous functions?
    A synchronous function will occupy Javascript continuously until its completion, an asynchronous function can be initiated and then put aside until a later date

  2. What is callback hell?
    A Callback hell is a situation when more complex operations tend to produce even more levels and sub-levels.

  3. Which technique can help us solve callback hell?
    Use promises to deal with excessive callback, for example jQuery ships with a simple built-in promise library that enables us to chain callbacks and deal with errors.

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#898

1.What is the difference between synchronous and asynchronous functions?
A synchronous task will occupy the program until completion.
An asynchronous task is initiated and then left while work continues on the next task.

2.What is callback hell?
Nested complexed callbacks which are harder to follow.

  1. Which technique can help us solve callback hell?
    Promises deals with errors & Fibers allows us to write code in a synchronous style.
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#899
  1. Synchronous functions block the programs further execution until something is done. Asynchronous functions do not block the program, and wait while the program thread
  2. Callback hell is when many functions are being performed in a nested form
  3. The use of promises can solve a callback hell situation
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#900

Q.1.What is the difference between synchronous and asynchronous functions?
A.1.Synchronous (blocking) are event handlers executed in sequence until completion, then the program will go onto the next event handler. The browser won’t respond to any events whatsoever while it completes the first handler

An Asynchronous task can be initiated and then put aside until the JavaScript engine uses
the the additional background thread to manage the event handler in a loop. The Asynchronous
code usually takes the form of Ajax. Ajax is most commonly used through a jQuery wrapper.
This method will not lock the browser up no matter how long it takes for the event handler to
complete.

Q.2. What is callback hell?
A.2 A large amount of nested functions to do a simple operation, such as logging into
an application.

Q.3.Which technique can help us solve callback hell?
A.3. For the browser the jQuery can use the built-in promise library. In Node.js the
technique would be to extend the runtime function to emulate the asynchronous
environment using the wait command.

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#901
  1. Synchronous functions lock up the webpage or server until they are completed. Asynchronous functions can be initiated, left to execute and returned to later for the results of their operation without the need to lock up the webpage or server while waiting for them to finish.
  2. Callback hell is where there are is a large set of nested functions for asynchronous operations.
  3. The use of “promises”. This technique allows chaining of callbacks and deals with errors.
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