ft_atoi.c

Go to the documentation of this file.

/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   ft_atoi.c                                          :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: unite <marvin@42.fr>                       +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2019/09/04 23:56:29 by unite             #+#    #+#             */
/*   Updated: 2020/07/16 03:05:43 by unite            ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */
 
#include "libft.h"
#include <limits.h>
 
int     ft_atoi(const char *str)
{
    int         i;
    int         num;
    int         is_neg;
 
    i = 0;
    is_neg = 0;
    num = 0;
    while (str[i] == ' ' || str[i] == '\t' || str[i] == '\n' || str[i] == '\v'
    || str[i] == '\f' || str[i] == '\r')
        i++;
    if (str[i] == '-')
        is_neg = 1;
    if (str[i] == '-' || str[i] == '+')
        i++;
    while (str[i] >= '0' && str[i] <= '9')
    {
        num *= 10;
        num += (str[i] - '0');
        i++;
    }
    return (is_neg ? -num : num);
}