この関数は Google スプレッドシートでも Excel と同じように機能します。構文も引数も同じです。
ISTEXT(value)The ISTEXT function is a logical function that determines whether the referenced value is a text string. It returns TRUE if the value is text, and FALSE if it is a number, error, logical value, or empty cell.
=ISTEXT("Excel")結果: TRUE
Returns TRUE because the input is a text string.
=ISTEXT(123)結果: FALSE
Returns FALSE because the input is a number.
Yes, if a number is stored as text (e.g., with an apostrophe prefix), ISTEXT will return TRUE.