Is 0 a decimal literal or an octal literal?

c++ zero octal
Yakov Galka picture Yakov Galka · Aug 1, 2011 · Viewed 19k times · Source

Zero is always zero, so it doesn't matter. But in a recent discussion with a friend he said that octal literals are almost unused today.† Then it dawned upon me that actually almost all integer literals in my code are octal, namely 0.

Is 0 an octal literal according to the C++ grammar? What does the standard say?

† The only real use I'm aware of is for unix file permissions.

Answer

Alok Save picture Alok Save · Aug 1, 2011

Yes, 0 is an Octal literal in C++.

As per the C++ Standard:

2.14.2 Integer literals [lex.icon]

Related questions

Can I check in C(++) if an array is all 0 (or false)?

Can I check in C(++) if an array is all 0 (or false) without iterating/looping over every single value and without allocating a new array of the same size (to use memcmp)? I'm abusing an array of bools to have …

Read More
Easiest way to convert int to string in C++

What is the easiest way to convert from int to equivalent string in C++. I am aware of two methods. Is there any easier way? (1) int a = 10; char *intStr = itoa(a); string str = string(intStr); (2) int a = 10; stringstream ss; ss &…

Read More
The Definitive C++ Book Guide and List

This question attempts to collect the few pearls among the dozens of bad C++ books that are published every year. Unlike many other programming languages, which are often picked up on the go from tutorials found on the Internet, few …

Read More