Map Lookup Shape

Maps make lookup code direct when the program needs to find a value by key.

map_lookup_shape.go

package main

import "fmt"

func main() {
	var key = 
	scores := map[string]int{
		"alpha": 3,
		"beta":  5,
		"gamma": 8,
	}
	value, ok := scores[key]
	result := "miss"
	if ok {
		result = "hit"
	}

	fmt.Println("key=", key)
	fmt.Println("value=", value)
	fmt.Println("found=", ok)
	fmt.Println("result=", result)
}

package main

import "fmt"

func main() {
	var key = 
	scores := map[string]int{
		"alpha": 3,
		"beta":  5,
		"gamma": 8,
	}
	value, ok := scores[key]
	result := "miss"
	if ok {
		result = "hit"
	}

	fmt.Println("key=", key)
	fmt.Println("value=", value)
	fmt.Println("found=", ok)
	fmt.Println("result=", result)
}

package main

import "fmt"

func main() {
	var key = 
	scores := map[string]int{
		"alpha": 3,
		"beta":  5,
		"gamma": 8,
	}
	value, ok := scores[key]
	result := "miss"
	if ok {
		result = "hit"
	}

	fmt.Println("key=", key)
	fmt.Println("value=", value)
	fmt.Println("found=", ok)
	fmt.Println("result=", result)
}

lookup Performance decisions often start with choosing a data shape that matches the operation: scan a slice or look up a key.