Explanation
One limitation of the IF function is that it does not support wildcards like "?" and "*". This means you can't use IF by itself to test for text that may appear anywhere in a cell.
One solution is a formula that uses the IF function together with the SEARCH and ISNUMBER functions. In the example shown, we have a list of email addresses, and we want to extract those that contain "abc". In C5, the formula were using is this:
=IF(ISNUMBER(SEARCH("abc",B5)),B5,"")
If "abc" is found anywhere in cell B5, IF will return that value. If not, IF will return an empty string (""). In this formula, the logical test is this bit:
ISNUMBER(SEARCH("abc",B5))
This snippet will return TRUE if the the value in B5 contains "abc" and false if not. The logic of ISNUMBER + SEARCH is explained in detail here.
To copy cell the value in B5 when it contains "abc", we provide B5 again for the "value if true" argument. If FALSE, we supply an empty string ("") which will display as a blank cell on the worksheet.
