Lesson 10 · Logic

ISBLANK, ISNUMBER & IS Functions

Test what is in a cell with ISBLANK, ISNUMBER, ISTEXT and ISERROR in Google Sheets, including the ISNUMBER(SEARCH()) "contains" trick.

Task 1 of 5

Some tasks have no owner yet. Return TRUE in C2 if the Owner cell B2 is empty.

Tip: while typing a formula, click a cell or drag across cells to insert references. Press Enter to check, and Tab to accept a function suggestion.

Asking "what's in this cell?"

The IS functions each answer a yes/no question about a value and return TRUE or FALSE:

Function	TRUE when the value…
`ISBLANK`	is a completely empty cell
`ISNUMBER`	is a number (dates count too)
`ISTEXT`	is text
`ISERROR`	is any error

They're most useful inside IF, e.g. =IF(ISBLANK(B2), "Unassigned", B2), and for data validation checks.

The "contains" trick

SEARCH returns a position when it finds text and an error when it doesn't. Wrap it in ISNUMBER and you get a clean TRUE/FALSE "does this cell contain…?" test:

=ISNUMBER(SEARCH("refund", A2))