C语言函数实现16进制字符串转十进制整数

#include <stdio.h> #include <stdlib.h> int conv(char hex[]){ int i, sum = 0, flag = 1; for(i = 0; hex[i] != '\0'; i++){ if(hex[i] == 'H' || hex[i] == 'h'){ if(i != (strlen(hex) - 1)) return -1; else break; } if(hex[i] >= '0' && hex[i] <= '9') sum = sum * 16 + hex[i] - '0'; else if(hex[i] >= 'A' && hex[i] <= 'F') sum = sum * 16 + hex[i] - 'A' + 10; else if(hex[i] >= 'a' && hex[i] <= 'f') sum = sum * 16 + hex[i] - 'a' + 10; else return -1; } return sum; }