Slice Length and Capacity in Golang

Application

Create new folder named src. In src folder, create new file named main.go as below:

package main

import (
	"fmt"
)

func main() {

	var a = [5]int{4, 1, -2, 9, 10}

	slice1 := a[0:2]
	fmt.Println("slice 1")
	fmt.Println("\tLength:", len(slice1))
	fmt.Println("\tCapacity:", cap(slice1))

	slice2 := a[:4]
	fmt.Println("slice 2")
	fmt.Println("\tLength:", len(slice2))
	fmt.Println("\tCapacity:", cap(slice2))

	slice3 := a[4:]
	fmt.Println("slice 3")
	fmt.Println("\tLength:", len(slice3))
	fmt.Println("\tCapacity:", cap(slice3))

	slice4 := a[:]
	fmt.Println("slice 4")
	fmt.Println("\tLength:", len(slice4))
	fmt.Println("\tCapacity:", cap(slice4))

}

Output

Open Terminal windows in Visual Studio Code and run command line: go run main.go

slice 1
        Length: 2
        Capacity: 5
slice 2
        Length: 4
        Capacity: 5
slice 3
        Length: 1
        Capacity: 1
slice 4
        Length: 5
        Capacity: 5