Pfthb

Sometimes I need to wait for a .forEach() method to finish, mostly on 'loader' functions. This is the way I do that:

$q.when(array.forEach(function(item) 
 //iterate on something 
)).then(function() 
 //continue with processing 
);

I can't help but feel that this isn't the best way to wait for a .forEach() to finish. What is the best way to do this?

forEach is not asynchronous, for example in this code:

array.forEach(function(item) 
 //iterate on something 
);
alert("Foreach DONE !");

you will see the alert after forEach finished.

var foo = [1,2,3,4,5,6,7,8,9,10];

If you're actually doing async stuff inside the loop, you can wrap it in a promise ...

var bar = new Promise((resolve, reject) => 
 foo.forEach((value, index, array) => 
 console.log(value);
 if (index === array.length -1) resolve();
 );
);

bar.then(() => 
 console.log('All done!');
);

The quickest way to make this work using ES6 would be just to use a for..of loop.

const myAsyncLoopFunction = async (array) 
 const allAsyncResults = 

 for (const item of array) 
 const asnycResult = await asyncFunction(item)
 allAsyncResults.push(asyncResult)
 

 return allAsyncResults

Or you could loop over all these async requests in parallel using Promise.all() like this:

const myAsyncLoopFunction = async (array) 
 const promises = array.map(asyncFunction)
 await Promise.all(promises)
 console.log(`All async tasks complete!`)

No, it is blocking. Have a look at the specification of the algorithm.

So whatever the code which you put outside forEach will execute once foEach() is done.

array.forEach(function(item) 
 //iterate on something 
)
// @TODO this code will be executed once above block is done.