Map

Let's break down the provided Go code step by step:

package main

import (
    "fmt"
    "maps"
)
  • The code begins with the package declaration. In this case, it's a standalone program with the main package.

  • It imports two packages, "fmt" (for formatting and printing) and a custom package "maps."

func main() {
    // Create an empty map with string keys and int values
    m := make(map[string]int)

    // Assign values to keys in the map
    m["k1"] = 7
    m["k2"] = 13

    // Print the entire map
    fmt.Println("map:", m)

    // Retrieve and print the value associated with the key "k1"
    v1 := m["k1"]
    fmt.Println("v1:", v1)

    // Try to retrieve a value for a non-existent key "k3"
    v3 := m["k3"]
    fmt.Println("v3:", v3)

    // Print the length of the map
    fmt.Println("len:", len(m))

    // Delete the key "k2" from the map
    delete(m, "k2")
    fmt.Println("map:", m)

    // Clear the entire map
    clear(m)
    fmt.Println("map:", m)

    // Check if the key "k2" exists in the map using a blank identifier (_)
    _, prs := m["k2"]
    fmt.Println("prs:", prs)

    // Create and print a new map using a shorthand syntax
    n := map[string]int{"foo": 1, "bar": 2}
    fmt.Println("map:", n)

    // Create another map with the same content as "n" and check if they are equal
    n2 := map[string]int{"foo": 1, "bar": 2}
    if maps.Equal(n, n2) {
        fmt.Println("n == n2")
    }
}
  • The main function is where the program execution begins.

  • A map m is created with string keys and int values using the make function.

  • Key-value pairs are added to the map using the assignment operator (=).

  • The map is printed using fmt.Println.

  • The value associated with the key "k1" is retrieved and printed.

  • An attempt to retrieve a value for a non-existent key "k3" is made, and the result is printed.

  • The length of the map is printed using len.

  • The key "k2" is deleted from the map using the delete function.

  • The clear function is called to clear the entire map (Note: clear function should be defined somewhere in your code, but it's not provided in the snippet).

  • The existence of the key "k2" is checked using a blank identifier.

  • Another map n is created using a shorthand syntax and printed.

  • Another map n2 is created with the same content as n, and their equality is checked using a custom function maps.Equal.

Please note that the clear function is not defined in the provided code snippet. If you intend to use it, you need to define it in your code. Additionally, the custom package "maps" is imported, but its functions are not provided in the snippet. Ensure that the necessary functions from the "maps" package are available in your code for the program to work correctly.

Output

map: map[k1:7 k2:13]
v1: 7
v3: 0
len: 2
map: map[k1:7]
map: map[]
prs: false
map: map[bar:2 foo:1]
n == n2

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