Get-DuplicateContact

A script to locate duplicate or non-duplicate contacts between two .csv contact lists.

It is not just restricted to contacts as the project name implies, but really can compare between any two .csv lists. In fact you can use .json and .xml, just change the ConvertFrom-Csv to ConvertFromJson and ConvertFrom-Xml respectively.

Notes

Why not just use Compare-Object?

• Searches using hashtable keys should be faster than Compare-Object. When working with many thousands or millions of records, the difference will be significant
• Hashtables build a meta object which can be used to store metadata, e.g. object keys.
• Compare-Object is generally unintuitive at least to the author. .SideIndicator grouping is difficult to manage and debug.