How to store a a single array from a two dimensional array

Using Arduino Programming Questions
1

I have a two dimensional array initialized as such

uint8_t array2dimension [x][y];

and would like to store a row into a 1 dimension array/

//store a random row into array1dimennsion
int range = x - 0 + 1; 
uint8_t index =  rand() % range + 0;
uint8_t array1dimension[y] = array2dimension[index];

But the code above throws an error

> array must be initialized with a brace-enclosed initializer

2

This is an invalid array definition/initialization statement. Declare the 1D array elsewhere.

3

Use memcpy, or a pointer if you don't need to copy it

Here is an example aOob36 - Online C++ Compiler & Debugging Tool - Ideone.com

4

like this?

int8_t array1dimension[y];
array1dimension[y] = array2dimension[index];

This still throws an error though,

error: invalid array assignment

5

Post ALL the code, using code tags.

6

You need to do that with a for loop for each element in the row (or memcpy() if what you call a row is the last dimension of the array)

C++ does not copy subarays for you

If you don’t need the copy, you could get a pointer to the start of the row (array data is guaranteed to be contiguous)

7

Why? Will your code modify the new 1-D array while the original 2-D array MUST remain unchanged? If not just access the row you need in the original array.

8

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