??????????????????????
????1?????????
?????????????????????????????????????????????????????????????????????????????????????????????塣??????????е??????????????????????????????????????????????intsize = 0;
????2?????????
????????????д?????????????????????“;”??ɡ??磺s=(a+b+c)/2;
????3?????????????
??????printf();?????????????printf????á?
????4??????????????
????????????????????“{}”??????????????????? ???????????????“;”??? ?????????κβ?????????????????С?
??????????????if/switch??
????1??if??????????if/else if????????
??????if(????) ???
??????if(????) ???1 else ???2
??????
????if(????1) ???1
????else if(????2) ???2
????…
????else if(????n) ???n ...
????else ???n+1
??????1???????if??esle???ж?????????????????????Щ?????????????????к?????1???????Ч??
??????2??if????е???????????????????????????????????????????????????
??????3??else?????????????????????????if???
????2??switch???
????switch (????)
????{
????case???????? 1?????1;     break;
????case???????? 2?????2;     break;
??????
????case???????? n?????n;     break;
????default: ???n+1;          break;
????}
??????1??switch?????е????????????????????????????????case????????????????????????????
??????2????case?е??????????????????????????С????????case???????ü?break??????break??????к????case???
??????3??case????????????case??????????????????????
??????4??default?????????????淶??????д?????
?????????????
????1??for
????for(????1??????2??????3)
????{
????// ???
????}
???????????????????1??????????????
????????????????б???2???ж??
????????????????????????????????б???3??????е??????????????????????????????
????break????????switch??????У???????switch????????????????????????????????????????????????????switch??????????!??
????continue????????????????????б???3??????????????????????????????????????????????????????
????2??while????for?????Ч??
????while(????)
????{
????// ???;
????}
???????ж?????У?while???????????????е???????????С??????????????????????????while(1)???????break??????????
????3??do...while
????do
????{
????// ???;
????}while (????);
????????????????????ж???????????? true???????????????
????while????????????ж??????????true ???????????
????dowhile??????????ж??????????????????塣
????// ?ж?????
????#include
????using namespace std;
????int main(void)
????{
????//????
????long m;
????cout << "please input a number: ";
????cin >> m;
????//????
????for(int i = 2; i < m; i++) //??m??????
????{
????if(m % i == 0)
????{
????break;
????}
????}
????//???
????if(m == i) //?ж?m???С??m????????
????{
????cout << m << " is prime. ";
????}
????else
????{
????cout << m << " isn't prime. ";
????}
????return 0;
????}