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snippets/js/s/array-to-csv.md

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+---
+title: Array to CSV
+type: snippet
+language: javascript
+tags: [array,string]
+cover: sunrise-over-city
+dateModified: 2020-11-03T21:55:08+02:00
+---
+
+Converts a 2D array to a comma-separated values (CSV) string.
+
+- Use `Array.prototype.map()` and `Array.prototype.join()` to combine individual 1D arrays (rows) into strings, using the provided `delimiter`.
+- Use `Array.prototype.join()` to combine all rows into a CSV string, separating each row with a newline (`\n`).
+- Omit the second argument, `delimiter`, to use a default delimiter of `,`.
+
+```js
+const arrayToCSV = (arr, delimiter = ',') =>
+  arr
+    .map(v =>
+      v.map(x => (isNaN(x) ? `"${x.replace(/"/g, '""')}"` : x)).join(delimiter)
+    )
+    .join('\n');
+```
+
+```js
+arrayToCSV([['a', 'b'], ['c', 'd']]); // '"a","b"\n"c","d"'
+arrayToCSV([['a', 'b'], ['c', 'd']], ';'); // '"a";"b"\n"c";"d"'
+arrayToCSV([['a', '"b" great'], ['c', 3.1415]]);
+// '"a","""b"" great"\n"c",3.1415'
+```