C\C++字符串转化成整数

1、字符串转化成整数

int StrToInt(const char *ch)
{
bool m_stat = false;
long num = 0;
int m_flag = 1;
assert(ch);
while(isspace(*ch))
++ch;
if(*ch == '-')
m_flag = -1;
if(*ch == '-' || *ch == '+')
++ch;
while (isdigit(*ch) && *ch )
{
num = num * 10 + m_flag*(*ch - '0');
if ((m_flag == 1 && num < 0)
|| (m_flag == -1 && num >0)) //判断溢出
{
num = 0;
break;
}
++ch;
if(*ch == '\0')
m_stat = true;
}
if(m_stat)
cout<<"SUCCESS"<<endl;
else
cout<<"FAIL"<<endl;
return num;
}

判断溢出还不是太清楚。