atoi 的简单实现

简单实现atoi 待改进


unsigned int atoi(char *str)
{
unsigned int result=0;
char *temp=str;
while(*temp)
{
if(*temp<'0'||*temp>'9')
{
printf("wrong string\n");
return 0;
}
temp++;
}
while(*str)
{
result *= 10;
result += (*str++-'0');
}
return result;
}