Quoted Field Parser - CSV Browser

A small parser keeps commas inside quoted fields while splitting a CSV row into cells.

Program

CSV files often contain commas inside quoted values. A parser has to track quote state before splitting on commas.

quoted_field_parser.html

<pre id="raw">name,notes
Ada,"ships, reviews"</pre>
<table id="grid"></table>
<script>
  const raw = document.querySelector("#raw");
  const grid = document.querySelector("#grid");
  const row = raw.textContent.trim().split("\n")[1];
  let quoted = false;
  const cells = row.split("").reduce((parts, char) => {
    if (char === "\"") quoted = !quoted;
    else if (char === "," && !quoted) parts.push("");
    else parts[parts.length - 1] += char;
    return parts;
  }, [""]);
  grid.innerHTML = "<tr>" + cells.map(cell => `<td>${cell}</td>`).join("") + "</tr>";
</script>

quoted fields A quoted CSV field can contain commas that are data, not delimiters.

parser state The parser needs state to know whether it is inside quotes.