ft_atoi.c

/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   ft_atoi.c                                          :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: aalvarez <aalvarez@student.42.fr>          +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2022/08/17 01:07:26 by aalvarez          #+#    #+#             */
/*   Updated: 2022/08/17 19:22:12 by aalvarez         ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */

#include "libft.h"

/**
 * @brief converts the string pointed by
 * str to its integer representation.
 * 
 * @param str the string containing the integer to be represented.
 * @return int the result of the representation of the string
 * pointed by str.
 */
int	ft_atoi(const char *str)
{
	int	result;
	int	i;
	int	sign;

	i = 0;
	sign = 1;
	while (str[i] == ' ' || (str[i] >= 9 && str[i] <= 13))
		i++;
	if (str[i] == '-' || str[i] == '+')
	{
		if (str[i] == '-')
			sign = -1;
		i++;
	}
	result = 0;
	while (str[i])
	{
		if (!ft_isdigit(str[i]))
			break ;
		result = result * 10 + (str[i++] - 48);
	}
	return (result * sign);
}