So in the beginning of my career I was working for a project where I had to deal with a lot of arrays and objects. Also there was a requirement of an asynchronous task within the loop!
On taking up the task I was like, "Eh, I'm going to complete this thing in no time and then watch an episode ;-)".
for () { await *db_call* }
But then as soon as I finished up writing my code, I tested it (just the response as I was too confident of the logic and implementation) and was surprised to see "undefined undefined undefined.....".
Now "How to do an asynchronous task in a loop?" is a separate post. Here I will talk about how I approached looping.
JavaScript has way too many methods to loop and doing asynchronous tasks within each one has a different level of difficulty but since this post is for beginners, the most basic loop is the for loop.
Yup, talking about the omnipresent for(var i = 0; i<limit; i++){}.
If we are talking about ES6, we also get very basic and easy to use (with easy to do async tasks facility) for-in and for-of loops.
What I learned is what I am going to share with you in the simplest way possible.
Syntax: for(let item in array){} -> item will hold index of arrays
Syntax: for(let item of array){} -> item will hold element of arrays
Therefore, we can also call them as:
for-in ->
for(let index in array)
{
// body
}
for-of ->
for(let element of array)
{
// body
}
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