Update a key in the map in Go (Golang)

When trying to add a key to the map which already exists, the new value will override the old value. This is analogous to updating a key in the map.

Let’s see an example

package main

import "fmt"

func main() {
    //Declare
    employeeSalary := make(map[string]int)

    //Adding a key value
    fmt.Println("Before update")
    employeeSalary["Tom"] = 2000
    fmt.Println(employeeSalary)

    fmt.Println("After update")
    employeeSalary["Tom"] = 3000
    fmt.Println(employeeSalary)
}

Output

Before update
map[Tom:2000]
After update
map[Tom:3000]

In the above program after writing the same key “Tom” with a new value of 3000 it overwrites the existing value of 2000. When we print the map again the value printed is 3000