changing datatypes in C, C++

Question

Hi, I can't find the solution, can any one help me?
How to convert a variable from int to float or an other data type?

int num1 = 10;

I wan't to convert this to a float or a double
so I can do this:

float num2 = 5,5;
num1 += num2;
num1 is equal to 15,5 and of type float;

Thanks

Answer 1

Yes Robin Rademaker, that's right, there's no way to change a declared variable from one type into another in C/C++, because it's against the strongly typed language characteristic 👍

Answer 2

Since you want the final value (sum of num1 + num2) to be a floating point type, you also need to use float for the final value. If you do `num1 += num2;` while num1 is an int you'll end up with 15 instead of 15.5, the fraction will be removed.

int num1 = 10;
float num2 = 5.5;
// The mix needs to be of the
// float type
float mix = (float)num1 + num2;

Hth, cmiiw

Answer 3

Yes that's right Division by Zero, but since the OP (Original Poster) used int for num1 this would be the way : )

Answer 4

Wouldn't it make more sense to just make num1 a float in that case?

Answer 5

ok I get that but I din't find anywhere how to change the data type of a variable
So I'm thinking now that once declared as a int the variable stays an int.
Yes y can pas the value to another variable but y can't change the data type of the same variable right?

Answer 6

Use casting.

num1 += (int)num2