operate ints and doubles

[infinity42]

Hey guys just a quick question - If i multiply an int with a double will if work out? For example will:

int integer = 2;
double decimal = 1.6;
double result = integer * decimal;

this cause result to equal 3.2? will c++ automatically typecast? Thanks a bunch guys for all the help you've been.

[jlb]

Did you enter that code into your compiler? Does it compile? Does it produce the results you expect?

[MiiNiPaa]

Yes, it will.
in yor case result will be 3.2
If you did: int result = integer * decimal; result will be 3;

Note that in case of

int x = 5;
int y = 2;
double result = x / y;

result will be 2, Because both operands of operator/ in this case are integer and so integer division will be performed. If you want to get 2.5 you should cast at least one operand to double manually:
double result = static_cast<double>(x)/y;>

[Stewbond]

MiiNiPaa:
Question question: I've never understood the difference between:
double result = static_cast<double>(x)/y;
and
double result = double(x) / y;

Can you explain?

[infinity42]

jlb:
My compilers been messing with me...People have compiled my code and it works but when i run it through mine it doesn't so I haven't been trusting my compiler too much for the past couple days.

MiiNiPaa:
Ok thanks, that makes sense.

[jlb]

My compilers been messing with me...People have compiled my code and it works but when i run it through mine it doesn't so I haven't been trusting my compiler too much for the past couple days.

Then I really suggest you get it fixed. You can't learn to program in C/C++ with a faulty compiler.

[MiiNiPaa]

@Stewbond
http://programmers.stackexchange.com/questions/50442/c-style-casts-or-c-style-casts