why does printf("a" "b" "c") prints abc in C [duplicate]

Question

I have the following code in C:

#include<stdio.h>
void main(){
    printf("a" "b" "c");
}

it outputs:

abc

Can anyone explain why?

I am guessing that it is "a" "b" "c" preprocessed as "abc". Am I right or Is it something else?

Answer 1

Adjacent string literals are concatenated as part of translation phase 6.

Brief summary of phases (source: C99 standard, paraphrased)

1. Trigraphs and multi-byte characters in the source file are mapped to the source character set
2. Lines ending in \ are spliced
3. File parsed into a set of preprocessing tokens
4. Preprocessing directives processed
5. Character constants and string literals are migrated to the execution character set
6. Adjacent string literals are concatenated.
7. The rest of compilation (excluding linking)
8. Linking

Answer 2

Adjacent string literals are merged in compilation translation phase 6. Since "a" "b" "c" is further treated as "abc" string literal.

In case of you are not familiar with this term, phase 6 is somewhat between preprocessing and actual, "proper" compilation.