Asynchronous Programming - Reading Assignment

Javascript Programming
#121

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

                  Synchronous functions run continuously until its completion, an *asynchronous* function can be started and then and the other processing can be completed while the first function is running.

  2. What is callback hell?

               Callback hell in JavaScript is when nested code is used to delay a function and the code becomes difficult to read or follow.

  3. Which technique can help us solve callback hell?

                    In the browser, through the use of "promises" or browser triggers provided in  jQuery. Or, extending runtime using "Fibers" via Node.js.
#122
  1. What is the difference between synchronous and asynchronous functions?

A sync task involves executing one line of code or command or something like that and putting everything else on the website on hold till that code is executed. Async involves programming it so that allows the code to be paused for the time being and then resumed later on so that one execution sequence doesn’t hold up the entire set of code from running.

  1. What is callback hell?

Callback hell occurs when there are two many subfunctions so that it’s hard to tell what’s supposed to come first and what’s sync and what’s async.

  1. Which technique can help us solve callback hell?

You can either use Jquery library “promises” which are designed to solve callback issues, or if you’re using node.js utilize “fibers” to make the code look sync even when it’s async, even though it’s not. It’s about rewriting the code in a such a way so that it feels sync even it can’t be.

#123
  1. The difference between synchronous and asynchronous functions is, synchronous functions are executed one section of code at a time. Asynchronous functions can initiate one section of code and set it aside to be completed at a later time, and move on to another section of code.
  2. Callback hell is the amount of nested functions/sub levels inside a piece of code. More complex operations produce more levels and sub levels.
  3. One technique that can help us solve callback hell is called Promises. Its a built-in JQuery library that helps us chain callbacks and deal with errors.
#124
  1. What is the difference between synchronous and asynchronous functions?
    synchronous functions use the single-thread program in order to execute a function until its finished, while asynchronous functions permit multitasking, in a way that it runs the code and realease the single-thread from that call function, those functions will be calledback once they get a data response.
  2. What is callback hell? event running a nested function, this means that a function code could be running in differents levels functions inside of his process, making the code very complex to read and maintain.
  3. Which technique can help us solve callback hell?
    By using the jquery library “built-in promise” in order to deal and solve erros.
#125

  1. What is the difference between synchronous and asynchronous functions?
    Single-threaded step by step code execution is synchronous, parallel task managing, minimizing the waiting time by introducing the Ajax-Callback method is asynchronous function.

  2. What is callback hell?
    Considering the multi layered nested functions, the callback of main function will depend on call back of other functions.

  3. Which technique can help us solve callback hell?
    Extending the runtime or built in promises.

#126
  1. Synchronous function: It waits for the completion of each operation, only after which it performs the following operation.
    Asynchronous function: is a form of I / O processing that allows you to continue processing other tasks without waiting for the transfer to complete.
  2. Asynchronous JavaScript or JavaScript that uses callbacks is something that is difficult to understand intuitively. Мore complex operations have shape of the pyramid with levels and sub-levels, which is called - callback hell.
  3. In the browser, a common pattern to deal with excessive callbacks is to use promises. This is a special object that contains its state. Initially, pending (“waiting”), then - one of: fulfilled (“completed successfully”) or rejected (“completed with an error”).
#127
  1. Synchronous program dosn’t allow other function to start until the first one is finished.
    Asynchronous programs allow other functions to execute if the first function is taking some time to respond.
  2. Nesting of many functions to implement complex operations is known callback hell.
  3. Promises can be used to deal with callback hell.
#128
  1. What is the difference between synchronous and asynchronous functions? Synchronous functions execute one at a time, i.e. won’t jump to the next until the current is completed. Such is the case in single-threaded environment. Asynchronous functions are such that one can be initiated and put aside so the other function/s can start executing.
  2. What is callback hell? It is the requirement of multi-level nested functions to execute an operation.
  3. Which technique can help us solve callback hell? The use of promises is common in browsers, and jQuery ships with a built-in promise library. In Node.js, the approach is writing code that looks synchronous thru extension of runtime.
#129

  1. What is the difference between synchronous and asynchronous functions?
    Single threaded. Each one waiting for the next to run vs simultaneous execution.

  2. What is callback hell?
    A bunch of call backs in a row filling up a large section of code and becoming hard to read. Also relating to synchronous code having long load times.

  3. Which technique can help us solve callback hell?
    Asynchronous programming and promises.

#130
  1. What is the difference between synchronous and asynchronous functions?
    Sync function occurs one after another and not allow next function to execute before previous one is complete. Async allows next function to run in another thread before the previous function is completed.
  2. What is callback hell?
    A nested event handlers which allows code to become async. It make code harder to write, debug and maintain.
  3. Which technique can help us solve callback hell?
    We can use promises to resolve the problem. Promised help to deal with chained sync functions and allows us to do error handling.
1 Like
#131
  1. What is the difference between synchronous and asynchronous functions?
  • A synchronous function occupies the JavaScript engine until the function is fully executed, which means that the program is blocked and no other functions can be executed in the meantime.
  • An asynchronous function can be initiated and then put aside until a later date, which means that the program is not blocked and can execute other functions before the first function is fully executed.
  1. What is callback hell?
  • A callback hell is when a program calls a function that calls an additional function within the initial function and then it continues to call more functions within the previous functions.
  1. Which technique can help us solve callback hell?
  • To solve a callback hell you can use promises or extend the runtime by writing code that looks synchronous.
#132

  1. What is the difference between synchronous and asynchronous functions?
    Synchronous functions - Only one section of the code in the function can run at any one time.
    Asynchronous functions - More than one section of the code in the function can run at any one time.

  2. What is callback hell?
    Even a relatively simple operation requires three levels of nested functions, when using many nested elements you create a lot of callbacks, which add up quickly and become very messy and hard to navigate. Almost like hell…

  3. Which technique can help us solve callback hell?
    There are multiples techniques for solving callback hell. One being promises, which chains callbacks and deals with errors

#133 
1. What is the difference between synchronous and asynchronous functions?

Synchronous or blocking functions occupy JS’s event handler fully. The tasks required are handled one after the other, they cannot happen simultaneously. An asynchronous task can be initiated and then set aside until late, while the event handler is beginning other things. This is done by the JS engine which takes care of the event loop.

2. What is callback hell?

Callback hell is the nesting of functions in various levels and sub-levels in excessive fashion. This makes the code harder to read and maintain.

3. Which technique can help us solve callback hell?

The use of promises that come from libraries such as jQuery. In Node.js you can extend the runtime of your code, making asynchronous functions look like synchronous ones, without blocking the browser or server in that instance, like a synchronous function would.

#134

  1. Synchronous functions are functions that are execute code line by line. Asynchronous functions are functions when several lines of code can be executed at the same time.

  2. Callback hell means that you have multiple functions that are asynchronous. Those functions depend on each other, which might, in turn, get quite messy with a lot of callback function that is nested in multiple layers. This will result in chaos, and you will end up with code which is hard to read and maintain.

  3. Promise is used to solve callback hell issue.

#135

  1. What is the difference between synchronous and asynchronous functions? A synchronous function is executed from the start to the end without executing other tasks, instead an asynchronous function doesn’t block the JS thread because it has some tasks that require to wait an answer from an external source before they can be executed.

  2. What is callback hell? It’s a negative consequence of nesting event handlers in the code to manage many asynchronous tasks. This situation increase complexity in the reading, updating and debugging the program code.

  3. Which technique can help us solve callback hell? Promises allows to chain callbacks and deal with errors, which helps make the code easier to read and manage.

#136
  1. What is the difference between synchronous and asynchronous functions? Synchronous is single threaded operation of a computer program: execute action A and wait for it to fully complete before moving onto action B. Asynchronous is the concept of ‘multi-threading’ computer language: run operation A and then, while waiting for data to come back from a website, or server, or where ever, set a ‘callback’ placeholder for whatever information that will be that is coming back, and go ahead and do operation B in the meantime. Asynchronous is definitely a more efficient use of time.
  2. What is callback hell? Callback hell is when, in the asynchronous situation described above, there are too many callbacks out and the situation gets confused. Is the information from the server back for this callback? The next one is waiting, and there are two more that are depending on that they will be heading in completely different directions, code-wise. Losing track of all the call backs gets into the realm of callback hell.
  3. Which technique can help us solve callback hell? At the browser level, jQuery uses the concept of promises, on the server level, nodejs slows the runtime down to simulate sychronous behavior.
#137

1. What is the difference between synchronous and asynchronous functions?
Synchronous functions operate only one function at a time, or single threaded, which means that all other functions must wait until the function running is complete before they can begin. Asynchronous functions can run in the background so that multiple functions can run at once.
2. What is callback hell?
This is when you have many layers of functions nested within each other.
3. Which technique can help us solve callback hell?
We can use the promises library to deal with callback hell.

#138

  1. What is the difference between synchronous and asynchronous functions?
    Synchronous functions occur sequentially. One task must finish before the next task begins.
    Asynchronous functions can be initiated and then set aside until a later time (allowing other tasks to be completed during this time).

  2. What is callback hell?
    It is JavaScript code written asynchronously in which one callback is nested into another callback, which is nested into another callback, which is nested into…etc. It produces messy code that is difficult to maintain.

  3. Which technique can help us solve callback hell?
    The concept and implementation of “Promises” can help us solve the problem of callback hell.

#139

1 - Synchronous functions, once started executing, will only stop after completing the calculations, while asynchronous functions can pause execution to resume at some given point later.
2 - Callback hell is a situation where, in order to execute some task, calling several functions within functions is needed.
3 - In the browser, promises can be used in order to deal with callback hells, while in Node.js, it is possible to abstract away the asynchronicity by extending the runtime.

#140
  1. Syncrhonous functions are single thread functions one says one task at a time what they call Javes. On the other hand asyncrhonous functions allow to be paused in order to start another task and finish the first one later.
  2. Callback hell is a poetic name for nested functions that bring too much complexity.
  3. Promises or async await syntax