C++ question

Question

Goodmorning, afternoon and evening all.

I have a question. I recently finished the C++ course on Sololearn. I am following now an another course to get some more practical experience but this course is making me little bit confused because of what I have learned at the Sololearn course.

For example: in Sololearn I have learned to declare a variable like this:

int myVarr = 12;
In this new course they declare a variable like this:
int myVarr {12};

Does this has to do with a newer version of C++?

What make me even more confused is that they declare a variable also like this:

int myVarr { addTwo(i)};
Do you know how I am supposed to read this?

Answer 1

Initializing a variable with {} is called uniform initialization ( C++11 ).
It makes variable initialization more consistent.
Arrays are initialized with {}, so why not variables.

int i = 12 and int i{12} do the same thing.

Additionally it protects you from things like uninitialized variables and from narrowing conversions.

int i; // dunno what i contains
int i{}; // i is default initialized to 0
---
int i = 2.5; // Fine
int i{ 2.5 }; // Error, narrowing conversion

However, just like most things in C++, even these things have a bunch of pitfalls, especially when working with auto, initializer_lists or templates.

Just use whichever you find more convenient.

Answer 2

https://blog.quasardb.net/cpp-braced-initialization/

Answer 3

Thank you Dennis and Daniel :) You both have helped me a lot :)