refactor: slice exercises 19-21

16-slices/exercises/20-observe-the-cap-growth/solution/main.go

@@ -15,15 +15,22 @@ func main() {
 		oldCap float64
 	)
 
+	// loop 10 million times
 	for len(nums) < 10e6 {
+		// get the capacity
 		c := float64(cap(nums))
 
+		// only print when the capacity changes
 		if c == 0 || c != oldCap {
+			// print also the growth ratio: c/oldCap
 			fmt.Printf("len:%-15d cap:%-15g growth:%-15.2f\n",
 				len(nums), c, c/oldCap)
 		}
+
+		// keep track of the previous capacity
 		oldCap = c
 
+		// append an arbitrary element to the slice
 		nums = append(nums, 1)
 	}
 }