ft_atoi.c

/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   ft_atoi.c                                          :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: jonchoi <jonchoi@student.42seoul.kr>       +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2022/07/15 04:29:56 by jonchoi           #+#    #+#             */
/*   Updated: 2022/07/15 18:56:31 by jonchoi          ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */

#include "libft.h"

int	ft_atoi(const char *str)
{
	int	num;
	int	sign;
	int	i;

	num = 0;
	sign = 1;
	i = 0;
	while (str [i] == ' ' || (str[i] >= 9 && str[i] <= 13))
		i++;
	if (str [i] == '-' || str [i] == '+')
	{
		if (str[i] == '-')
			sign *= -1;
		i++;
	}
	while (str[i] >= '0' && str[i] <= '9')
	{
		num = (num * 10) + (str[i] - '0');
		i++;
	}
	return (sign * num);
}