Javascript-根据数量变量循环遍历次数

Question

I have the following javascript object

[Object { url="http://domain.com/abc", qty="1" }, Object { url="http://myurl.com/cde", qty="2" }]

I want to be able to loop through the object and output the URL using console.log() based on the qty variable.

So in this instance domain.com/abc would display once & the myurl.com/cde would display twice as the qty is set to 2.

I have something like the following but needs some work..

cart.forEach(function(value) {
   var qty = value.qty;
   var url = value.url;
   var i = 0;

   while ( i < qty ) {
     // logic needed here (i believe)
     i++;
   }
}

Answer 1

That's how one can implement String.repeat in JS:

var repeatedString = Array(repeatsCount + 1).join(stringToRepeat);

... so in your case it'll be just ...

console.log(Array(+value.qty + 1).join(value.url));

Unary plus is a shortcut for Number(value.qty) : it looks like you got a string there.

---

But it looks you actually need to collect all the urls instead. That's one possible way to do that:

var arrayOfUrls = [];
cart.forEach(function(value) {
   for (var i = value.qty; i--) {
     arrayOfUrls.push(value.url);
   }
});

Alternative (.reduce-based):

var arrayOfUrls = cart.reduce(function(arr, value) {
  for (var i = value.qty; i--) {
     arr.push(value.url);
  }
  return arr;
}, []);