stack.go

stack.go

package main

import (
	"errors"
	"fmt"
)

type Stack struct {
	s []int
}

func NewStack() *Stack {
	stack := Stack{
		s: make([]int, 0),
	}
	return &stack
}

func (s *Stack) push(val int) {
	s.s = append(s.s, val)
}

func (s *Stack) isEmpty() bool {
	if len(s.s) == 0 {
		return true
	}
	return false
}

func (s *Stack) pop() (int, error) {
	length := len(s.s)
	if length == 0 {
		return 0, errors.New("empty stack")
	}

	result := s.s[len(s.s)-1]
	s.s = s.s[:length-1]

	return result, nil
}

func main() {
	stack := NewStack()
	stack.push(1)
	stack.push(2)
	stack.push(3)
	stack.push(4)
	fmt.Println(stack.s)
	val, _ := stack.pop()
	fmt.Println(val)
	val, _ = stack.pop()
	fmt.Println(val)

	fmt.Println(stack.s)
}