docs.sheetjs.com/docz/docs/12-constellation/01-ssf.md

title	hide_table_of_contents
SSF Number Formatter	true

As explained in "Number Formats", modern spreadsheet file formats separate "content" from "presentation". Instead of storing a formatted value like $3.50, applications will store the underlying value (3.50) and the number format ($0.00). Parsers are expected to render values.

The SheetJS SSF ("SpreadSheet Format") library formats numbers according to the number formatting rules defined in Excel and other spreadsheet software¹

A version of the library ships with the main file processing library. It is deeply integrated in SheetJS CE API functions including read², write³, and sheet_to_json⁴.

The library is also available for standalone use on the SheetJS CDN⁵.

Source code and project documentation are hosted on the SheetJS git server at https://git.sheetjs.com/sheetjs/sheetjs/src/branch/master/packages/ssf

Live Demo

The formatted text is calculated from the specified number format and value. Please report an issue if a particular format is not supported.

function SheetJSSSF() {
  const [fmt, setFmt] = React.useState("#,##0");
  const [val, setVal] = React.useState(7262);
  const [text, setText] = React.useState("");

  React.useEffect(() => {
    let v = +val;
    if(!isFinite(v)) return setText(`ERROR: ${val} is not a valid number!`);
    try {
      setText(XLSX.SSF.format(fmt, v));
    } catch(e) { setText("ERROR: " + (e && e.message || e)); }
  }, [fmt, val]);
  const goodstyle = { backgroundColor: "#C6EFCE", color: "#006100" };
  const badstyle = { backgroundColor: "#FFC7CE", color: "#9C0006" };

  return ( <table>
    <tr><td><b>Number Format</b></td><td>
      <input type="text" value={fmt} onChange={e => setFmt(e.target.value)}/>
    </td></tr>
    <tr><td><b>Number Value</b></td><td>
      <input type="text" value={val} onChange={e => setVal(e.target.value)}/>
    </td></tr>
    <tr><td colspan="2"></td></tr>
    <tr><td><b>Formatted Text</b></td><td>
      <code style={/ERROR/.test(text)?badstyle:goodstyle}>{text}</code>
    </td></tr>
  </table> );
}

---

1. The number formatting rules are sketched in ECMA-376. A rough grammar is defined in the MS-XLS specification. ↩︎

2. See read in "Reading Files" ↩︎

3. See write in "Writing Files" ↩︎

4. See sheet_to_json in "Utilities" ↩︎

5. See https://cdn.sheetjs.com/ssf/ for more details. ↩︎