--- sidebar_position: 7 title: Array of Formulae --- **Extract all formulae from a worksheet** ```js var fmla_arr = XLSX.utils.sheet_to_formulae(ws); ``` `XLSX.utils.sheet_to_formulae` generates an array of commands that represent how a person would enter data into an application. ## Live Preview After choosing a file, the demo will extract and display all formulae. ```jsx live function SheetJSFormulaPreview() { const [__html, setHTML] = React.useState("Select a file"); return ( <> <pre dangerouslySetInnerHTML={{ __html }}/> <input type="file" onChange={async(e) => { const wb = XLSX.read(await e.target.files[0].arrayBuffer()); var res = ""; wb.SheetNames.forEach((n, idx) => { const ws = wb.Sheets[n]; res += `<b>Sheet #${idx+1} (${n})</b>\n`; res += XLSX.utils.sheet_to_formulae(ws).join("\n") + "\n\n"; }); setHTML(res); }}/> </> ); } ``` ## Cell Processing Cells are analyzed in "row-major order" (starting from the first row). #### Cells without formulae Cells without formulae are written as `A1-cell-address=value`: ``` A1=1 // A1 is the numeric value 1 B1=TRUE // B1 is the logical value TRUE ``` String literals are prefixed with a `'` in accordance with Excel: ``` A5='A4+A3 // A5 is the string "A4+A3" ``` #### Cells with formulae Cells with formulae are written as `A1-cell-address=formula`: ``` A5=A4+A3 // A5 is a cell with formula =A4+A3 ``` #### Array formulae Array formulae are written as `A1-range=formula`. They do not include the displayed curly braces: ``` A4:B4=A2:B2*A3:B3 // A4:B4 array formula {=A2:B2*A3:B3} ``` Single-cell array formulae are written with single-cell ranges: ``` C4:C4=SUM(A2:A3*B2:B3) // C4 array formula {=SUM(A2:A3*B2:B3)} ``` ## Demo This example constructs a workbook including cells with no formulae, cells with normal formulae, single-cell array formulae and array formulae spanning ranges. For verification, the button writes a workbook whose formulae can be inspected. ```jsx live function SheetJSToFormulae() { var ws = XLSX.utils.aoa_to_sheet([ ["A", "B", "C"], [1, 2, { t: "n", f: "SUM(A2:B2)" }], [3, 4, { t: "n", f: "A3+B3" }] ]); XLSX.utils.sheet_set_array_formula(ws, "A4:B4", "A2:B2*A3:B3"); XLSX.utils.sheet_set_array_formula(ws, "C4", "SUM(A2:A3*B2:B3)"); const generate = () => { const wb = XLSX.utils.book_new(); XLSX.utils.book_append_sheet(wb, ws, "Sheet1"); XLSX.writeFile(wb, "SheetJSFormulae.xlsx"); }; var __html = `\ <i>Values</i> [ ["A", "B", "C"], [ 1 , 2], [ 3 , 4] ] <i>Formulae</i> C2 =SUM(A2:B2) C3 =A3+B3 <i>Array Formulae</i> A4:B4 {=A2:B2*A3:B3} C4 {=SUM(A2:A3*B2:B3)}`; return ( <pre> <b>Original worksheet</b><br/> <button onClick={generate}><b>Export worksheet to XLSX</b></button> <div dangerouslySetInnerHTML={{__html}}/><br/> <b>XLSX.utils.sheet_to_formulae(ws).join("\n")</b><br/> <br/>{XLSX.utils.sheet_to_formulae(ws).join("\n")} </pre> ); } ```