经典案例--十六进制转换为十进制_松下plc 转16进制

1、方法一 用一级指针

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
 
int convert(char *myp, int mylen, int *Poutput)
    {
    int i = 0;
    char *pstart = myp + 1;
    char *Pstop = myp + mylen - 1;
    int ant = 0;
    int hex = 1;
 
    if(Pstop == NULL )
    {
        return -1;
    }
 
    if(myp == NULL)
        {
        return -1;
    }
 
    while(Pstop > pstart)
        {
        for(i = 0; i < mylen - 2; i++)
            {
            if(*Pstop >= 'A' && *Pstop <= 'F')
                {
                ant = ant + (*Pstop - 'A' + 10) * hex;
            }
            else
                {
                ant = ant + (*Pstop - '0') * hex;
                }
                Pstop --;
                hex = hex * 16;
            }
    }