C+ multiplying a double with an undeclared number

Question

Hi masterminds,

I have an operation to multiple a double (already declared, say double x) with an undeclared variable (e.g.

x *= (1.0 + 0.05 * 3 * 2)

)

What would happen? Would this return a number with the same precision as x (i.e. 14 significant numbers)?

Thanks!!!

Answer 1

(1.0 + 0.05 * 3 * 2) is a literal expression. Meaning it is an expression that uses numeric literals and since 1.0 or 0.05 will be evaluated as a double implicitly, the entire expression shall be evaluated as a double, because it is the largest type used in the expression.
Since x is a double and the expression is a double there will be no further conversion and therefore no issue.
However, if x were an int you'd have an error due to implicit lossy conversion. (Trying to implicitly put a larger type in a smaller container).
If the expression was made up solely of integers (int) and x were to remain a double, an implicit conversion would take place without issue, because double is a compatible larger type than int.

Answer 2

C+ is not a language.