C++ -> Which is faster?? int a(5); or int a = 5;

Question

I know this is easy one but I'm confused whether int a (5); is faster than int a=5; in C++, as I read somewhere, if a constructor with only one parameter is defined in the class, the initialisation can be done with an equal sign.(A statement can be written with an equal sign) So I thought may be first one is bit of a extra Work.

It's equivalent. Feel free to test, but it's equivalent. Your own quote doesn't claim a difference; it's still initialization either way, and that's the same work for the same thing. — ShadowRanger, Dec 22 '20 at 12:12
There are many more ways to do initialization in C++ than just those two. If you have an hour, you may be interested to watch the presentation [The Nightmare of Initialization in C++](https://www.youtube.com/watch?v=7DTlWPgX6zs) by Nicolai Josuttis. — Eljay, Dec 22 '20 at 12:22

score 6 · Accepted Answer · answered Dec 22 '20 at 12:13

The two forms tell the compiler the same thing in different ways (the statements have the same ultimate meaning). Since the compiler is told the same thing, it should generate the same code.

(It is theoretically possible somebody could design a compiler to do different things with these statements, but that would be a bad design.)

score 1 · Answer 2 · answered Dec 22 '20 at 12:17

1

Both should run within the same period. Even the quote you put doesn't suggest anything that shows a difference in performance.

answered Dec 22 '20 at 12:17

Moataz Alsayed

381
2
12

C++ -> Which is faster?? int a(5); or int a = 5;

2 Answers2