Asynchronous Programming - Reading Assignment

[JasonB]

1. What is the difference between synchronous and asynchronous functions? synchronous functions run in order, ie one after the other has completed. Asynchronous functions are able to run at the same time and don’t need the previous function to have completed.

2. What is callback hell? When you have several asynchronous functions all awaiting data to be returned at once.

3. Which technique can help us solve callback hell? By utilising the fibers package in Meteor, we can write synchronous looking code, that will actually be run as asynchronous code. Otherwise, jquery ships with a simple promise library, for slightly less callback hell scenarios.

[Terri]

1. What is the difference between synchronous and asynchronous functions?
   In synchronous functions only one section of the code can run at any one time. In asynchronous functions, more than one section of the code can run at any one time.

2. What is callback hell?
   Simple operations require three levels of nested functions. So complex operation tend to produce more levels and sub-levels, this is called callback hell.

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

[0xinu]

1. What is the difference between synchronous and asynchronous functions?
   an asynchronous function can be initiated and then put aside until a later date
2. What is callback hell?
   It’s difficult sometimes to keep track of all the functions nested inside a program
3. Which technique can help us solve callback hell?
   Promises and async / await

[king_smit]

1. Synchronous functions are single-threaded functions; whereas asynchronous functions are functions that aren’t time dependent and are non-blocking. This means that the latter can manage multiple process events, or that any one sections of code can be run at any one time; while the latter works top-down, waiting for each step to be executed before the next is started.
2. Callback hell, happens when we have obscene amounts of nested dependent functions. This makes it very hard to read and manage errors/control flow of a program/process.
3. Promises can solve callback hell by allowing us to chain callbacks and resolve errors in that fashion. Extending the run time of nested functions is another solution, giving issues time to be resolved, and write code that looks synchronous.

[SimonLondon]

What is the difference between synchronous and asynchronous functions?
A synchronous function will continue until it is finished and thereby stopping anything else running. A asynchronous function can be suspended until an event has fired and control returned to the main thread for the execution of other tasks.

What is callback hell?
It is when the number of nested functions involving callbacks becomes so complex that the code becomes extremely difficult to follow and understand.

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

[Antonio_Andara]

1. What is the difference between synchronous and asynchronous functions?
   synchronous programs occupy the JavaScript event handler completely and the tasks are performed sequentially. An asynchronous functions may be initiated and then put aside while the main thread is running other tasks

2. What is callback hell?
   it is the accumulation of nested functions which makes it very difficult to read and maintain

3. Which technique can help us solve callback hell?
   we can use promises to do this

[Gab]

• What is the difference between synchronous and asynchronous functions?
  Synchronous function don’t let the execution of the code to proceed until they are resolved, making all the subsequent code “wait” and hence slowing down the overall loading time of the project; instead asynchronous functions send an external request and without waiting for the answer carry on with the execution of the code, and then come back to resolve the function when the external request sent already came back with the answer.

• What is callback hell?
  Callback hell is a funny way to call the annoying situation in where to resolve a relatively simple task we need to use multiple nested functions, making our code difficult to read and error prone.

• Which technique can help us solve callback hell?
  A popular way to deal with callback hell is a built-in feature if jQuery that helps us to link callbacks and deal with errors.

[biffen96]

What is the difference between synchronous and asynchronous functions?
an asynchronous function can be initiated and then put aside until a later date

What is callback hell?
It’s difficult sometimes to keep track of all the functions nested inside a program

Which technique can help us solve callback hell?
Promises and async / await

[AnCaPepe]

1. What is the difference between synchronous and asynchronous functions?: synchronous functions block execution of the main program until they are completed. Asynchronous ones are able to run in parallel and return at another point

2. What is callback hell?: It’s the complex nesting of callback functions that you end up getting when making your code more asynchronous

3. Which technique can help us solve callback hell?: Some custom or library-provided abstractions

[Piotr]

@ivan

What is the difference between synchronous and asynchronous functions?

Synchronous functions are executing one line after another even if they have to wait for answer for a long time. Asynchronous functions allows to execute another functions in the time of waiting for answer.

@ivan

What is callback hell?

It’s the hell of functions that to execute needs another functions to be executed and that functions also needs another functions to be executed and that functions also needs another functions to be executed and that functions also need another functions to be executed and that functions also need another functions to be executed… What a hell!!!

@ivan

Which technique can help us solve callback hell?

Well, I don’t know exactly yet but I’am good and promising . I’ve heard that JQuery has a special library for that at this point.

[Raulitiu]

1. What is the difference between synchronous and asynchronous functions?
   Synchronous functions are functions that occup javes full atention, and asynchronous functios are initiated and put aside untill a later date while another function is executed.

2. What is callback hell?
   A callback hell is more complex operations of levels and sublevels.

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

[CurlyBracketEffect]

1. Synchronous functions take up the main thread until they are done executing. whereas asynchronous functions will wait for a response in another event loop.

2. Call back hell is when you you have a chain of functions in your code that is really hard to read.

3. We can use asynchronous functions to help clean up callback hell.

[Mark1]

1. What is the difference between synchronous and asynchronous functions?
In synchronous programming, each step is performed one after the previous one is finished executing. In asynchronous, step 2 will be performed even if step 1 isn’t finished.

2. What is callback hell?
Callback hell is any code where the use of function callbacks in async code becomes obscure or difficult to follow. Generally, when there is more than one level of indirection, code using callbacks can become harder to follow, harder to refactor, and harder to test.

3. Which technique can help us solve callback hell?
   Write comments, Split functions into smaller functions, Use Promises, Use Async/await.

[MrGanD]

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

Synchronous or blocking functions occupy JavaScripts full attention and lock up the browser until its completion while asynchronous functions can be initiated and then put aside via event loop.

2. What is callback hell?

In asynchronous programming even a relatively simple operation can requires multiple levels of nested functions. That is why more complex operations produce even more levels and sub-levels, which is what creates so called callback hell.

3. Which technique can help us solve callback hell?

We can use jQuery built-in promise library that chains callbacks and deal with errors or in Node.js we can simulate synchronicity.

[simplyprado]

1. Synchronous function executes the code from top to bottom of the file sequentially. In the case where the code contains asynchronous functions, these asynchronous functions execute separately from the main program, based on the instructions given to the asynchronous function.

2. Callback hell is a situation where several functions are being performed in nested form.

3. Promise is used to solve the call back hell situation.

[bl0ckchain_br0thaman]

1. synchronous functions block the program execution until they are finished, while asynchronous functions permit multitasking, in the sense that they send the request and liberate the program execution until they are called back

2. Callbacks within callbacks, within callbacks to a degree when maintaining and reading a program becomes sloppy

3. The use of promises can solve a callback hell situation

[chaneltiana]

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

• Asynchronous functions can be initiated then put to aside until a later date while the synchronous functions have to complete each task in the order given.

2. What is callback hell?

• Callback hell is where the use of function callbacks in async code becomes difficult to follow.

3. Which technique can help us solve callback hell?

• To solve callback hell in jQuery, we can use promises to enable us to chain callbacks and deal with errors.

[markfoster]

1. Synchronous functions is where every task is waited for and completed until moving on to the next task which is alright because computers perform these tasks instantly. However it is not good if you are calling upon api’s or sourcing things from a third part site. This is where asynchronous functions come in handy. They start a task and then complete other tasks while you wait for the information to come back from the first task.

2. When complex operations have many levels and sub levels of nested functions.

3. A technique to help with callback hell is to use promises which is used by a simple built in library on jQuery.

[swisscrypto]

@ivan

• What is the difference between synchronous and asynchronous functions?
• What is callback hell?
• Which technique can help us solve callback hell?

A synchronous function occupies JavaScript’s full attention during the process, since only one section of code can be running at any one time.
An asynchronous function is used when querying a server for data or making an API call. While the function is waiting for the reply (awaiting the execution of a promise), it is put aside and JavaScript can start on a new task. As soon as the reply arrives from the server, JavaScript will return the promise.

“Callback hell” is a subjective impression that the developer may feel when he/she is overloaded with heavily nested asynchronous code (with levels and sub-levels) that becomes overly complex to manage. (A callback is a handler that responds to an Ajax event fired by the browser.)

In the browser, a good way of dealing with callback hell is to use promises. As a matter of fact, jQuery contains a simple built-in promise library that enables developers to chain callbacks and deal with errors.
In Node.js, we can abstract away the asynchronicity by extending the runtime and write code that looks synchronous.

[jjkkll09]

1. Synchronous functions are functions that complete one at a time. Asynchronous functions that partially complete then complete later on.
2. Callback hell is when you have more than one nested asynchronous functions in a row.
3. Promises and Meteor can be used to solve callback hell.