Question

Sorry for this simple question, but I can’t solve it…

There is an example:

int a[10] = {6, 7.8, 8.0, -6, -5.7, 5, 5.7};

std::cout << a[6 % 8 / 4 + 21 % 9];

In response I get -5, but I don’t understand why.

Answer 1

http://en.cppreference.com/w/cpp/language/operator_precedence
Operators have their priority so in this case: 6 % 8 / 4 + 21 % 9 = (((6%8)/4)+(21%9))=(6/4)+(3)=4

a[0]=6,
a[1]=(int)7.8 = 7, (correct me if i'm wrong)
a[2] = (int)8.0 = 8,
a[3] = -6,
a[4] = (int)-5.7 = -5,
a[5] = 5,
a[6] = (int)5.7 = 5

So element with index 4 it’s -5.7 casted to integer gives -5 (the rest is just cut off)