C++: How to declare an array at the top of the method?

Question

I'd like to declare an array at the top of my method, but it's not compiling:

Foo Bar()
{
    int arr[]; // C2133

    // …

    // C2059, C2143, C2143
    arr[] = {1, 2, 3}; 
}

What am I doing wrong here?

UPDATE I know that C++ doesn't force me to do it this way, but the project's convention wants all variables declared at the top of their method.

Answer 1

When you declare an array in C/C++, you need to specify the size. If you do not specify the size, then you need to define the array elements in the same declaration statement, like this:

int arr[] = {1, 2, 3};

Answer 2

It's just invalid syntax. If you want to do arr = { ... };, it has to be when you declare the variable. But C++ doesn't force you to declare the variable at the start of the function, so you could do:

Foo Bar() {
    // other stuff goes here
    // ...
    int arr[] = {1, 2, 3};
}

Answer 3

You cannot. Either the project's convention needs to give, or your initialization code does:

Foo Bar() {
    int a[3];
    ...
    a[0] = 1;
    a[1] = 2;
    a[2] = 3;
}