What it does: THE INDEX() Function returns a value based on the array of values you select and the row and column within that array (column is optional).
Plain English: This formula will help quickly you locate values within an array. It is very often used with the MATCH formula to quickly match up two sets of data and return the values you need. A simple example would be looking up an Employee Name based on his/her ID Number. If you only had the ID, but also had a mapping table of ID -> Employee Name, this formula would quickly look up the ID and return the name of the employee you’re searching for.
Arguments: INDEX(array, row #, [column #])
- Array – The list of values you want to search through
- Row # – Which row within the Array do you want to search?
- [Column #] – Which column within the Array do you want to search? (optional)