String to Integer (atoi)

Implement atoi to convert a string to an integer.

Hint: Carefully consider all possible input cases. If you want a challenge, please do not see below and ask yourself what are the possible input cases.

Notes: It is intended for this problem to be specified vaguely (ie, no given input specs). You are responsible to gather all the input requirements up front.

public int myAtoi(String str) {    int index = 0, sign = 1, total = 0;    //1. Empty string    if(str.length() == 0) return 0;    //2. Remove Spaces    while(str.charAt(index) == ' ' && index < str.length())        index ++;    //3. Handle signs    if(str.charAt(index) == '+' || str.charAt(index) == '-'){        sign = str.charAt(index) == '+' ? 1 : -1;        index ++;    }    //4. Convert number and avoid overflow    while(index < str.length()){        int digit = str.charAt(index) - '0';        if(digit < 0 || digit > 9) break;        //check if total will be overflow after 10 times and add digit        if(Integer.MAX_VALUE/10 < total || Integer.MAX_VALUE/10 == total && Integer.MAX_VALUE %10 < digit)            return sign == 1 ? Integer.MAX_VALUE : Integer.MIN_VALUE;        total = 10 * total + digit;        index ++;    }    return total * sign;}