two problom help me

[47803124]

1.int GetPrices(int &m, int &a, int &b) This is a fucion of get price,buy i can't understand the "&" is mean,why add the symb

2. int start = FileOpenHistory(Symbol() + Period() + ".hst", FILE_BIN|FILE_READ);

int m=FileReadInteger(start);

Print(m);

why the up code output is 400,why

[William Roeder]

zdj231: int GetPrices(int &m, int &a, int &b) This is a fucion of get price,buy i can't understand the "&" is mean,why add the symb

void ByValue(int x,int y){
  x++; y++
  Print("y="+x+" y="+y); // x=3 y=4
}
void ByReference(int& x,int& y){
  x++; y++
  Print("y="+x+" y="+y); // x=3 y=4
}
:
int a=2, int b=3;
Print("a="+a+" b="+b); // a=2 b=3
ByValue(a,b);
Print("a="+a+" b="+b); // a=2 b=3
ByReference(a,b)
Print("a="+a+" b="+b); // a=3 b=4

[47803124]

WHRoeder:

what's the cal principle

[GreenMoney]

See also the documentation for Formal parameters regarding passing parameters by reference.