Home >Backend Development >C++ >\'const int\' vs. \'int const\': Does Keyword Placement Matter in C ?
The Enigma of "const int" and "int const": A Tale of Equivalence and Distinction
In the realm of C programming, the placement of the "const" keyword may raise questions about its implications. Consider the following code snippets:
<code class="cpp">int const x = 3; const int x = 3;</code>
Are both code snippets syntactically correct? Moreover, do they convey the same meaning?
The Answer:
To answer these questions, we must delve into the intricacies of constant declarations in C . Surprisingly, both snippets are indeed valid and equivalent. They declare an integer variable named "x" with a constant value of 3, meaning its value cannot be modified throughout the program's execution.
The Distinction:
However, when dealing with pointer types, the order of "const" and the type specifier does make a difference. Let's examine the following examples:
<code class="cpp">// Declares a constant pointer to an int const int *p = &someInt; // Declares a pointer to a constant int int * const p = &someInt;</code>
In the first case, the pointer "p" points to an integer that cannot be modified through the pointer. In the second case, "p" itself cannot be changed to point to a different integer but the data it points to can be modified.
Therefore, when using constant declarations in C , it is crucial to consider the placement of the "const" keyword, especially when working with pointer types. Understanding these subtle distinctions is essential for writing robust and error-free code.
The above is the detailed content of \'const int\' vs. \'int const\': Does Keyword Placement Matter in C ?. For more information, please follow other related articles on the PHP Chinese website!