JavaScript: Converts a comma-separated values string to a 2D array

JavaScript fundamental (ES6 Syntax): Exercise-3 with Solution

CSV String to 2D Array

Write a JavaScript program to convert a comma-separated value (CSV) string to a 2D array.

Note: Use String.split('\n') to create a string for each row, then String.split(delimiter) to separate the values in each row. Omit the second argument, delimiter, to use a default delimiter of ,. Omit the third argument, omitFirstRow, to include the first row (title row) of the CSV string.

• Use Array.prototype.slice() and Array.prototype.indexOf('\n') to remove the first row (title row) if omitFirstRow is true.
• Use String.prototype.split('\n') to create a string for each row, then String.prototype.split(delimiter) to separate the values in each row.
• Omit the second argument, delimiter, to use a default delimiter of ,.
• Omit the third argument, omitFirstRow, to include the first row (title row) of the CSV string.

Sample Solution:

JavaScript Code:

// Source: https://bit.ly/2neWfJ2

// Define a function called `csv_to_array` that converts CSV data to an array.
const csv_to_array = (data, delimiter = ',', omitFirstRow = false) =>
  // Split the CSV data by newline characters, map each row to an array of values split by the delimiter.
  data
    .slice(omitFirstRow ? data.indexOf('\n') + 1 : 0)
    .split('\n')
    .map(v => v.split(delimiter));

// Test cases
console.log(csv_to_array('a,b\nc,d')); // [['a', 'b'], ['c', 'd']]
console.log(csv_to_array('a;b\nc;d', ';')); // [['a', 'b'], ['c', 'd']]
console.log(csv_to_array('head1,head2\na,b\nc,d', ',', true)); // [['a', 'b'], ['c', 'd']]

Output:

[["a","b"],["c","d"]]
[["a","b"],["c","d"]]
[["a","b"],["c","d"]]

Flowchart:

Live Demo:

See the Pen javascript-basic-exercise-1-3 by w3resource (@w3resource) on CodePen.

For more Practice: Solve these Related Problems:

• Write a JavaScript program that converts a CSV string into a two-dimensional array, correctly handling quoted commas.
• Write a JavaScript function that parses a CSV string with newline delimiters and returns an array of arrays.
• Write a JavaScript program that splits a CSV string into rows and columns while ignoring empty cells.

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