chapter02.markdown

Map of Arrays/Slices

Create nested map of arrays

moa := map[string][2]string{
  "Jan": [2]string{"a", "b"}, 
  "Feb": [2]string{"c", "d"}, 
}

Create nested map of slices

mos := map[string][]string{
  "Apr": []string{"a", "b"}, 
  "May": []string{"c", "d"}, 
}

Add an array.

moa["Mar"] = [2]string{"g", "h"}
mos["Jun"] = []string{"g", "h"}

Delete one map entry

delete(moa, "Jan")
delete(mos, "Apr")

mos["May"][0] = "Another"

Modify an entry in one of the nested maps. // Doesn't work! Is a copy: moa["Mar"][0] = "Illegal"

temp := moa["Mar"]
temp[0] = "formerG"
moa["Mar"] = temp

Extract one field

fmt.Printf("One value in a nested map: %v\n", moa["Feb"][0])

Extract one field

fmt.Printf("One value in a nested map: %v\n", mos["May"][0])

Extract one array

fmt.Printf("One array: %v\n",moa["Mar"])

Extract one slice

fmt.Printf("One array: %v\n",mos["Jun"])

by element

fmt.Println("Array -----")
for i := range(moa) {
  fmt.Printf("(%s) %v\n", i, moa[i])
  for j:=0; j<len(moa[i]); j++ {
    fmt.Printf(" (%s,%d) %v\n", i, j, moa[i][j])
  }
}

by element, same old...

fmt.Println("Slice -----")
for i := range(mos) {
  fmt.Printf("(%s) %v\n", i, mos[i])
  for j:=0; j<len(mos[i]); j++ {
    fmt.Printf(" (%s,%d) %v\n", i, j, mos[i][j])
  }
}

Entire DSC

fmt.Printf("Entire Map of Arrays: %v\n",moa)
fmt.Printf("Entire Map of Slices: %v\n",mos)