Go 言語の組み込みメソッドを深く理解するための実践的なヒント

func copy(dst, src []T) int

package main

import "fmt"

func main() {
    s1 := []int{1, 2, 3}
    s2 := make([]int, len(s1))

    copy(s2, s1)

    fmt.Println("s1:", s1)
    fmt.Println("s2:", s2)
}

package main

import "fmt"

func main() {
    s := []int{1, 2, 3}

    s = append(s, 4)

    fmt.Println("s:", s)
}

package main

import "fmt"

func main() {
    m := map[string]int{"a": 1, "b": 2, "c": 3}

    for key, value := range m {
        fmt.Printf("Key: %s, Value: %d
", key, value)
    }
}

package main

import "fmt"

func main() {
    m := map[string]int{"a": 1, "b": 2, "c": 3}

    delete(m, "a")

    fmt.Println("m after deletion:", m)
}

package main

import "fmt"

func main() {
    s1 := "Hello, "
    s2 := "Go!"

    result := s1 + s2
    fmt.Println(result)

    result2 := fmt.Sprintf("%s%s", s1, s2)
    fmt.Println(result2)
}

package main

import (
    "fmt"
    "strings"
)

func main() {
    s := "hello,world"

    parts := strings.Split(s, ",")
    fmt.Println(parts)
}