How to Pass References to Two-Dimensional Arrays in C ?

Passing References to Two-Dimensional Arrays in C

When working with functions that manipulate arrays in C , understanding how to pass references is crucial. This article will address the issue of how to pass a reference to a two-dimensional array to a function.

The provided error message, "error: expected ‘,’ or ‘...’ before ‘*’ token," indicates that the syntax for passing a reference to a two-dimensional array is incorrect. The correct syntax for doing so when the dimensions are known at compile time is:

<code class="cpp">void do_something(int (&array)[board_width][board_height]);</code>

In this syntax, the '&' symbol before 'array' indicates that a reference to the array is being passed. By using a reference, the function has a direct and mutable reference to the array, meaning any changes made to the array within the function will be reflected in the original array.

Alternatively, if you wish to pass a pointer to the first sub-array, use this syntax:

<code class="cpp">void do_something(int array[board_width][board_height]);</code>

However, this method will not provide a direct reference to the original array, and any changes made within the function will not be reflected in the original array.

It's important to note that when using references, the function parameter's size (in this case, 'board_width') can be dropped since the size is already known at compile time. Passing a pointer, on the other hand, requires specifying the size of the first dimension, as in 'int arrayboard_width'.

In summary, passing a reference to a two-dimensional array in C requires the use of '&' before the array parameter in the function prototype and ensures that changes made within the function are reflected in the original array. Understanding this concept helps avoid errors and ensures proper data manipulation within functions.

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