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Go Language Go Language Overview Data Structures Maps

Rizwan Khan
Rizwan Khan
24,089 Points
Posted by Rizwan Khan
Rizwan Khan
24,089 Points

How to return a new map in Go?

The HalfPriceSale function should receive a map with product name strings as its keys, and corresponding prices as its values, like this:

{"OCKOPROG": 89.99, "ALBOÖMME": 129.99, "TRAALLÅ", 49.99}

It should return a new map with all the same keys, but all the corresponding values divided in half, like this:

{"OCKOPROG": 44.995, "ALBOÖMME": 64.995, "TRAALLÅ", 24.995}

Here is my code:

src/sales/sales.go 
package sales

func HalfPriceSale(prices map[string]float64) map[string]float64 {
  for _, v := range prices {
   return v/2
  }
}

2 Answers

Steven Parker
Steven Parker
229,732 Points
Steven Parker
Steven Parker
229,732 Points

You'll need to build a new map in your function, then you can return it. Also, you won't want to return inside the loop, you'll want to wait until the loop finishes going through the entire data.

There's an example of building up a map in the first half of the Maps video.

Rizwan Khan
Rizwan Khan
24,089 Points
Rizwan Khan
Rizwan Khan
24,089 Points

Took me some time, but finally figured it out. Thanks for your help.

package sales

func HalfPriceSale(prices map[string]float64) map[string]float64 {
  newPrices := map[string]float64{}
  for k, v := range prices {
    newPrices[k] = v/2
  }
  return newPrices
}
Tony Brackins
Tony Brackins
28,766 Points
Tony Brackins
Tony Brackins
28,766 Points

I did the same but returned prices and didn't declare new var.