promise.all return value code example
Example: promise all in promise all
var arr = [
{subarr: [1,2,3]},
{subarr: [4,5,6]},
{subarr: [7,8,9]}
];
function processAsync(n) {
return new Promise(function(resolve) {
setTimeout(
function() { resolve(n * n); },
Math.random() * 1e3
);
});
}
Promise.all(arr.map(function(entity){
return Promise.all(entity.subarr.map(function(item){
return processAsync(item);
}));
})).then(function(data) {
console.log(data);
});