C17 (C standard revision)
C17, formally ISO/IEC 9899:2018, is an open standard for the C programming language, prepared in 2017 and published on 5 July 2018. It replaced C11, and is superseded by C23 since October 2024. Since it was under development in 2017, and officially published in 2018, C17 is sometimes referred to as C18.
Changes from C11
C17 fixes numerous minor defects in C11 without introducing new language features.The
__STDC_VERSION__ macro is increased to the value 201710L.For a detailed list of changes from the previous standard, see Clarification Request Summary for C11. Examples of changes include fixes for
#elif, realloc, and typos, among others.