HMKhoa Cng Ngh Thng Tin & Truyn Thngi Hc Cn ThCHNG
4:(FUNCTION)
HmMc tiuM t cch khai bo, nh ngha, v gi hmNi dungKhai bo hm, nh
ngha hmTham s, i s, phm viBin t ng, bin thanh ghi, bin ni tuyni s
mc nh, i s hng lnh
Chng 4
Hm L G?Mt phng thc ng gi qu trnh tnh ton d dng s dngnh ngha hm
Khai bo hmTn hmCc tham s ca hmKiu tr v ca hmMt phng thc ng gi qu
trnh tnh ton d dng s dngnh ngha hm Khai bo hmTn hmCc tham s ca
hmKiu tr v ca hmnh ngha hmCc lnhS dng hmGi hmTn hm( )Cc i sNhn kt
qu tr v ca hm
Chng 4
V D V HmTn hmCc tham sKhai bo hmnh ngha hmnh ngha hmCc i sChng
4
Phm Vi Ton Cc Cc BPhm vi ton ccc nh ngha phm vi chng trnhPhm vi
cc bc nh ngha phm vi khi hay hmTon t phm vi::int xyz = 1; // xyz l
ton ccvoid Foo (int xyz) // xyz l cc b cho thn ca Foo{ if (xyz >
0) { double xyz =2; // xyz l cc b cho khi ny cout
Bin T ng Thanh GhiBin t ngc xc nh hon ton t ngV d: int auto
sum;Bin thanh ghic lu tr trong thanh ghi tng hiu xut ca chng trnhV
d: for (register int i = 0; i < n; ++i) sum += i;
Chng 4
Hm Ni Tuyn QuiS dng hmThun li: chng trnh d c, tng kh nng s dng
li, trnh cc hiu ng phBt li: tn chi ph cho vic gi hmGii php: nh ngha
hm l ni tuyn (inline) quiMt hm gi chnh ninline int Abs (int n){
return n > 0 ? n : -n;}int Factorial (unsigned int n){ return n
== 0 ? 1 : n * Factorial(n-1);}Chng 4
i S Mc nh - Hng Lnhi s mc nhb bt i gnh nng phi ch nh cc gi tr ca
i s cho tt c cc tham s hmi s hng lnhC th nhn khng hay nhiu i s t
hng lnhc to ra sn cho mt chng trnh C++ thng qua hm mainV d: int
main (int argc, const char* argv[]);
