Please use JS with Eclipse

// 6) numberOfPairs /Return the number of times a pair occurs in array. A pair is any two String values that are equal (case // sensitive) in consecutive array elements. The array may be empty or have only one element. In both of // these cases, return 8 // numberOfPairs( ['a, 'b, 'c' returns // numberOfPairs(['a', 'a', 'a' returns 2 // assert(2numberOfPairs( ['a', 'a', 'b, 'b')) // numberOfPairs [ returns umberOfPairs( ['a']) returns // Precondition: arr has all the same type of elements numberofPairsi a