How to Simply Loops in typescript

Question

I want to remove loops by using linq query. Can anyone help me to do this.

 

for (var a in this.OrderItem) {

for (var b in this.items) {

  if (this.OrderItem[a].ItemId == this.items[b].Id) {

   this.items[b].IsOrderItem = true;

  this.items[b].FinalQuantity = this.OrderItem[a].Quantity;

  this.items[b].OrderItem = this.OrderItem[a].OrderSubItems;

  this.items[b].OrderItemId = this.OrderItem[a].Id;

  break;

}

}

}