Index operator bound to a string literal

Question

So I decided to experiment, completely out of randomness. And I found this:

"Hello World"[1]

Actually working on a first view, resulting in 'e' even though:

I haven't encounter this anywhere until happened to be in my code
Seems semantically controversial (or at least quite suspicious)
Could not find any information on the internet, regarding this positive string literal array indexing (probably searching in the wrong context?)

Is this actually allowed, confronting the "standards" with guaranteed well-defined behavior ?

possible duplicate of [Is literal string indexing standard C?](http://stackoverflow.com/questions/11503248/is-literal-string-indexing-standard-c) — too honest for this site, Jul 22 '15 at 22:16
I think S/O needs improvements concerning the questions searcher. — Imobilis, Jul 22 '15 at 22:26
No search engine can foresee the creativeness of askers on SO. It's all a matter of search phrase and memory (I had in mind there were such questions (sic! plural!). — too honest for this site, Jul 22 '15 at 22:30
Me either. I was closely certain that there is such question already. However, I could not find it so.. — Imobilis, Jul 22 '15 at 22:32
See also [question 6.11](http://c-faq.com/aryptr/q6.11.html) in the [C FAQ list](http://c-faq.com/). — Steve Summit, Jul 22 '15 at 22:41
When converting to decimal or hexadecimal strings it's not uncommon to see things like `*p++ = "0123456789"[n%10]` or `*p++ = "0123456789abcdef"[n%16]`. — Steve Summit, Jul 22 '15 at 22:49
@Malina Yeah the searcher is terrible. Using google with "site:stackoverflow.com" does better — M.M, Jul 22 '15 at 23:11

score 3 · Accepted Answer · answered Jul 22 '15 at 22:16

This is semantically correct. "Hello World"[1] is equivalent to *("Hello World" + 1). In this expression the string "Hello World" will be converted to pointer to its first element. Therefore, ("Hello World" + 1) is the address of second element of string "Hello World".

score 1 · Answer 2 · answered Jul 22 '15 at 22:15

1

"Hello World"[1]

is perfectly valid. A string literal is of type array of N characters. The type of "Hello World" is an array of 12 char (i.e., char[12]).

answered Jul 22 '15 at 22:15

ouah

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Index operator bound to a string literal

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