In JavaScript, does using await inside a loop block the loop?

Question

Take the following loop:

for(var i=0; i<100; ++i){
    let result = await some_slow_async_function();
    do_something_with_result();
}

Answer 1

As @realbart says, it does block the loop, which then will make the calls sequential.

If you want to trigger a ton of awaitable operations and then handle them all together, you could do something like this:

const promisesToAwait = [];
for (let i = 0; i < 100; i++) {
  promisesToAwait.push(fetchDataForId(i));
}
const responses = await Promise.all(promisesToAwait);