diff --git a/eBook/11.14.md b/eBook/11.14.md
index 67638b0..4613590 100644
--- a/eBook/11.14.md
+++ b/eBook/11.14.md
@@ -162,7 +162,7 @@ func (cs Cars) FindAll(f func(car *Car) bool) Cars {
 
 // Process cars and create new data.
 func (cs Cars) Map(f func(car *Car) Any) []Any {
-       result := make([]Any, 0)
+       result := make([]Any, len(cs))
        ix := 0
        cs.Process(func(c *Car) {
            result[ix] = f(c)