Is Variable Initialization with its Own Undeclared Value an Anomaly in C/C ?

Undeclared Variable Initialization: Exploring the Peculiarity

In C/C , a curious behavior arises when a variable is declared and initialized simultaneously using a newly introduced variable within the initialization expression, such as:

int x = x + 1;

This raises the question: Is this an intended behavior or a parser anomaly?

Variable Initialization,

The syntax int x = x 1; initializes the variable x while simultaneously declaring it. This initialization process occurs at the equality sign (=), allowing the variable to be utilized on the right-hand side.

However, unless the variable x has static storage duration (outside a function), its initial value is arbitrary, resulting in undefined behavior.

C Standard,

The C 03 standard specifies:

"The point of declaration for a name is immediately after its complete declarator (...) and before its initializer (if any)."

This implies that within the expression int x = x;, the second x within the initialization refers to its own undefined value.

**Parser Peculiarity or Intended Behavior?,

This peculiar behavior is not specific to GCC versions. It is an implementation of the C/C standard, which allows the initialization of a variable with its own newly declared value.

However, caution is advised when utilizing this approach, as it can potentially lead to unexpected results if the variable does not have static storage duration.

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