ft_atoi.c

/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   ft_atoi.c                                          :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: atabiti <atabiti@student.42.fr>            +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2021/11/07 13:50:02 by atabiti           #+#    #+#             */
/*   Updated: 2021/11/20 15:08:56 by atabiti          ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */

#include "libft.h"

int	ft_atoi(const char *str)
{
	int	i;
	int	n;
	int	positive;

	positive = 1;
	n = 0;
	i = 0;
	while (str[i] == ' ' || str[i] == '\n' || str[i] == '\t'
		|| str[i] == '\v' || str[i] == '\f' || str[i] == '\r')
		i++;
	if (str[i] == '+' || str[i] == '-')
	{
		if (str[i] == '-')
		{
			positive = -1;
		}
	i++;
	}
	while (str[i] >= '0' && str[i] <= '9')
	{
		n = 10 * n + (str[i] - '0');
		i++;
	}
	return ((int)n * positive);
}