在 Javascript 中循环对象值

Question

I have 3 objects.

obj([]);
obj([{name:'Jeans', quantity:5}]);
obj([{name:'Jeans-M-B', quantity:1},{name:'Jeans-S-R', quantity:7}]);

I am trying to add the quantity values together which should equal to 13. I can't seem to grasp on how to actually get the values. When I tried the code below, it just gives me the objects themselves instead of their values.

function obj(itemsObj) {

  var obj = Object.values(itemsObj);
  console.log(obj.quantity);
}

Answer 1

You can reduce the object's quantities to their sum:

 function quantities(obj) { return obj.reduce(function(acc, curr) { return acc + curr["quantity"] }, 0) } t = [{name:'Jeans-M-B', quantity:1},{name:'Jeans-S-R', quantity:7}]; console.log(quantities(t))

Answer 2

you are trying to pass an array into something that expects an object. To iuse Object.values, you would need to reference each index. In your case, you do not need to use it. You just loop over the array with reduce where you can read the quantity property.

 function getTotal (items) { return items.reduce( function (cnt, item) { return cnt + item.quantity }, 0) } /* const getTotal = items => items.reduce( (cnt, item) => cnt + item.quantity , 0) */ var total = getTotal([{name:'Jeans-M-B', quantity:1},{name:'Jeans-S-R', quantity:7}]); console.log(total)