What happens when we interchange the array name and index like index[arrayname] in C++? Is arrayname[index] the same as writing index[arrayname]? What will be the value in both?
2 Answers
For builtin types, the definition of E1[E2] "is identical (by definition) to" *((E1) + (E2)). (quotation from [expr.sub]/1) So the answer is simple: interchanging the names has no effect.
For user-defined types, E1 has to be a class type with an overloaded operator[], so, absent some funky stuff, you can't interchange the two expressions.
It has no effect since arrayname[index] is identical writing as index[arrayname] cause both are interpreted as:
*(arrayname + index)
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