ARRAYFORMULA Patterns for Google Sheets
Apply a formula to a whole column without dragging.
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Teach me ARRAYFORMULA patterns for my sheet. Layout (columns and what they contain): [LAYOUT]. What each calculated column should do: [CALCULATIONS]. Sample rows (fake): [SAMPLE_ROWS]. For each calculation, provide: - The array formula that fills the whole column from row 2, with the header written in the same formula where useful: =ARRAYFORMULA(IF(ROW(A:A)=1, "Total", IF(A:A="", "", B:B*C:C))) - A plain-language explanation of each part, including why the blank check prevents formulas filling empty rows. - A variant that is limited to a defined range for performance. - The behavior when new rows are added. Cover patterns: arithmetic across columns; text joins; IF logic; lookups using VLOOKUP inside ARRAYFORMULA or XLOOKUP; MAP/LAMBDA alternatives if available; running totals; counting duplicates with COUNTIF and MMULT-style alternatives; and splitting text. Warn about limits: outputs cannot overwrite existing cells; some functions do not work inside array formulas; blank handling; performance with long ranges; and how to debug by testing the formula on a single row. Include a before-and-after example showing a dragged formula column versus the array formula, and three test cases.
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