#include <iostream>
int main()
{
using namespace std;
int arr[] = {1,2,3,4,5}; //initialization
cout << -3[arr]; //line A
return 0;
}
How is the output of line A -4? Thanks in advance.
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463035818_is_not_an_ai
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Vishvajeet T
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Run here http://cpp.sh/4y6kp. Output is -4 every time. – Vishvajeet T Sep 19 '17 at 11:23
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6@tobi303 No UB here, the `operator[]` has higher precedence than unary minus. – Baum mit Augen Sep 19 '17 at 11:26
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@BaummitAugen arghs, missed that – 463035818_is_not_an_ai Sep 19 '17 at 11:27
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@tobi303 So did I at first, admittedly. – Baum mit Augen Sep 19 '17 at 11:28
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2`-3[arr]` is actually `-(3[arr])` – Gaurav Sehgal Sep 19 '17 at 11:28
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@BaummitAugen - Every time it amazes me how easy it is to forget C++ doesn't have negative integer literals. – StoryTeller - Unslander Monica Sep 19 '17 at 11:28
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@StoryTeller Yeah, but fortunately that's a dusty corner of the standard that's not relevant to real-world code. – Baum mit Augen Sep 19 '17 at 11:30
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`a[n]` == `*(a+n)` == `*(n+a)` == `n[a]`. 1st conversion is standard definition of array indexing. 2nd conversion is basic maths. 3rd conversion is reverse of 1st. – Richard Critten Sep 19 '17 at 12:00