clang++ - Declaration in if statement weird behaviour (C++) -

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this question has answer here:

i have following code:

int x = 1; if (int x = x) {     printf("%d\n", x);     if (int x = x)     {        printf("%d\n", x);     } }

my expectation x should 1, 1. however, output is:

1818935350 32767

anyone know what's going on here? compiled clang-800.0.42.1

edit: tried following code bit tweak, , behaves expected.

int x = 1; if (int y = x) {     printf("%d\n", y);     if (int z = x)     {         printf("%d\n", z);     } }

one guess when use variable on rhs of declaration inside if statement, might not refer variable same name declared @ parent scope, instead it's referring variable that's being defined...

when int x = x, both x's refer same int. is, 1 declaring right there in line. initializing x itself, undefined behavior, since (of course) not initialized. x initialized 1 never printed in code, since declared in parent scope , shadowed ones in inner scopes.


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