Notice: This page requires JavaScript to function properly.
Please enable JavaScript in your browser settings or update your browser.Lära Accessing Map Values | Intro to Structs & Maps
Introduction to GoLang

bookAccessing Map Values

We can access the value corresponding to a key in a map using the following syntax:

index.go

index.go

copy

              
1

            
mapName["keyName"]

For example:

index.go

index.go

copy

              
1234567891011121314

            
package main
import "fmt"

func main() {
	prices := map[string]int {
		"apple": 100,
		"banana": 120,
		"peach": 170,
	}

	fmt.Println(prices["apple"]) // Output: 100
	fmt.Println(prices["banana"]) // Output: 120
	fmt.Println(prices["peach"]) // Output: 170
}

The expression prices["apple"] essentially references the memory location where the value 100 is stored; hence, it acts like a variable. Therefore, we can edit the value stored at that key using the = operator:

index.go

index.go

copy

              
12345678910111213

            
package main
import "fmt"

func main() {
	prices := map[string]int {
		"apple": 100,
		"banana": 120,
		"peach": 170,
	}

	prices["apple"] = 160
	fmt.Println(prices["apple"]) // Output: 160
}

We can use the same assignment syntax to create a new key in the map:

mapName["keyName"] = value

If the provided keyName doesn't exist in the map, it will create and add a new key to the map with the assigned value.

index.go

index.go

copy

              
1234567891011121314151617

            
package main
import "fmt"

func main() {
	
	numbers := map[string]int {
		"one": 1,
		"two": 2,
		"three": 3,
	}
	
	fmt.Println(numbers) // Output: map[one:1 three:3 two:2]
	
	numbers["four"] = 4
	
	fmt.Println(numbers) // Output: map[four:4 one:1 three:3 two:2]
}
question mark

What will be the output of the following code?

Select the correct answer

Var allt tydligt?

Hur kan vi förbättra det?

Tack för dina kommentarer!

Avsnitt 6. Kapitel 6

Fråga AI

expand

Fråga AI

ChatGPT

Fråga vad du vill eller prova någon av de föreslagna frågorna för att starta vårt samtal

Awesome!

Completion rate improved to 1.96

bookAccessing Map Values

Svep för att visa menyn

We can access the value corresponding to a key in a map using the following syntax:

index.go

index.go

copy

              
1

            
mapName["keyName"]

For example:

index.go

index.go

copy

              
1234567891011121314

            
package main
import "fmt"

func main() {
	prices := map[string]int {
		"apple": 100,
		"banana": 120,
		"peach": 170,
	}

	fmt.Println(prices["apple"]) // Output: 100
	fmt.Println(prices["banana"]) // Output: 120
	fmt.Println(prices["peach"]) // Output: 170
}

The expression prices["apple"] essentially references the memory location where the value 100 is stored; hence, it acts like a variable. Therefore, we can edit the value stored at that key using the = operator:

index.go

index.go

copy

              
12345678910111213

            
package main
import "fmt"

func main() {
	prices := map[string]int {
		"apple": 100,
		"banana": 120,
		"peach": 170,
	}

	prices["apple"] = 160
	fmt.Println(prices["apple"]) // Output: 160
}

We can use the same assignment syntax to create a new key in the map:

mapName["keyName"] = value

If the provided keyName doesn't exist in the map, it will create and add a new key to the map with the assigned value.

index.go

index.go

copy

              
1234567891011121314151617

            
package main
import "fmt"

func main() {
	
	numbers := map[string]int {
		"one": 1,
		"two": 2,
		"three": 3,
	}
	
	fmt.Println(numbers) // Output: map[one:1 three:3 two:2]
	
	numbers["four"] = 4
	
	fmt.Println(numbers) // Output: map[four:4 one:1 three:3 two:2]
}
question mark

What will be the output of the following code?

Select the correct answer

Var allt tydligt?

Hur kan vi förbättra det?

Tack för dina kommentarer!

Avsnitt 6. Kapitel 6
some-alt