由兩個char變量、一個int變量、一個short變量組合成long類型,代碼如下:
char area = num;
char channel = 2;time_t tm;
time(&tm);
int timestamp = (int)tm;
srand(time(NULL));
unsigned short randnum = (unsigned short)rand()%65535;
long id;
id = (((long)area)<<56)|(((long)channel)<<48)|(((long)timestamp)<<16)|(((long)randnum));
實際爲移位操作,將某個變量移動到制定的組合後的類型位置。