=match and =index in Google sheet

=match(cell ref or value,

The value we are looking for,

=Match( , row or column reference,

Within a given row or column, say A1:A4

=match(.   ,.  , 0)
Type of match, zero is “exact”.

Returned value: the relative position in row or column the match is found. This can be used in index below 

INDEX

=INDEX (array, 

Say B2:C4

=INDEX ( , row position,

Row Position in array, 1 is first row

=INDEX ( , , column position)

Column position in array, 2 is second column.

Returned value: contents of cell at relative row and column within array

To add: simple and link to YouTube explanation

To investigate: what if multiple matches are found? Assume match will return position of first match in row/ column .

To investigate: position of last nkn-blank value. Assume: find position of first blank match and subtract 1 to find position of last non blank . Issue: no blanks interposed in data