expression trees - Output of C program -


this question has answer here:

int a[]={10,20,30,40}; int x=0;  int v=a[++x]+ ++x + a[--x]; printf("%d",v);

what output of program??

completely confused output. no way going done according operator precedence knowledge.

according me, in expression array subscripting [] has highest precendence , should executed first. both [] should executed first left right. in case value of x increment first, decrement , come 0. expression become int v=a[0] + ++x + a[0]. pre increment having highest precedence , incremented 1. our expression become int v=a[0]+1+a[0]. final output 21.

but not case. have checked on different compiler implementations , no 1 prints 21.

i surprised because value printed 43, no understandable me. that's why want me understand , come result 43.

the link others have suggested using increment , same rvalue , lvalue cases. different , not clear. tried contruct expression tree , solve 43 no in scope.

output of code:

int v=a[++x]+ ++x + a[--x];

is undefined , depends on compiler implementation.


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