Why Do Parentheses in C Variable Declarations Not Change the Type?

Parentheses in C Variable Declarations

Consider the following code:

<code class="cpp">int main() {
    int(s);
}</code>

The use of parentheses around the variable declaration int(s); may be unexpected, as it creates a valid variable named s. This behavior stems from a specific part of the C standard known as the "Meaning of Declarators Rule" found in [dcl.meaning].

According to this rule, when parentheses enclose a declaration, the type of the variable being declared remains unchanged. In your example, s is a declarator, and placing it within parentheses does not alter its type or meaning.

This feature allows for more complex declarations to be constructed. For instance, it can distinguish between an array of pointers and a pointer to an array:

<code class="cpp">int * a [10];     // a is an array of ten pointers to int.
int ( * b ) [10]; // b is a pointer to an array of ten ints.</code>

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