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30-seconds-of-code/snippets/CSVToJSON.md
Isabelle Viktoria Maciohsek 05e3f6dc07 Format snippets
2020-11-03 22:11:18 +02:00

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---
title: CSVToJSON
tags: string,object,advanced
---
Converts a comma-separated values (CSV) string to a 2D array of objects.
The first row of the string is used as the title row.
- Use `Array.prototype.slice()` and `Array.prototype.indexOf('\n')` and `String.prototype.split(delimiter)` to separate the first row (title row) into values.
- Use `String.prototype.split('\n')` to create a string for each row, then `Array.prototype.map()` and `String.prototype.split(delimiter)` to separate the values in each row.
- Use `Array.prototype.reduce()` to create an object for each row's values, with the keys parsed from the title row.
- Omit the second argument, `delimiter`, to use a default delimiter of `,`.
```js
const CSVToJSON = (data, delimiter = ',') => {
const titles = data.slice(0, data.indexOf('\n')).split(delimiter);
return data
.slice(data.indexOf('\n') + 1)
.split('\n')
.map(v => {
const values = v.split(delimiter);
return titles.reduce(
(obj, title, index) => ((obj[title] = values[index]), obj),
{}
);
});
};
```
```js
CSVToJSON('col1,col2\na,b\nc,d');
// [{'col1': 'a', 'col2': 'b'}, {'col1': 'c', 'col2': 'd'}];
CSVToJSON('col1;col2\na;b\nc;d', ';');
// [{'col1': 'a', 'col2': 'b'}, {'col1': 'c', 'col2': 'd'}];
```