Example JavaScript code to parse CSV data

Question

Where could I find some JavaScript code to parse CSV data?

Answer 1

Here's another solution. This uses:

• a coarse global regular expression for splitting the CSV string (which includes surrounding quotes and trailing commas)
• fine-grained regular expression for cleaning up the surrounding quotes and trailing commas
• also, has type correction differentiating strings, numbers and boolean values

For the following input string:

"This is\, a value",Hello,4,-123,3.1415,'This is also\, possible',true

The code outputs:

[
  "This is, a value",
  "Hello",
  4,
  -123,
  3.1415,
  "This is also, possible",
  true
]

Here's my implementation of parseCSVLine() in a runnable code snippet:

function parseCSVLine(text) {
  return text.match( /\s*(\".*?\"|'.*?'|[^,]+)\s*(,|$)/g ).map( function (text) {
    let m;
    if (m = text.match(/^\s*\"(.*?)\"\s*,?$/)) return m[1]; // Double Quoted Text
    if (m = text.match(/^\s*'(.*?)'\s*,?$/)) return m[1]; // Single Quoted Text
    if (m = text.match(/^\s*(true|false)\s*,?$/)) return m[1] === "true"; // Boolean
    if (m = text.match(/^\s*((?:\+|\-)?\d+)\s*,?$/)) return parseInt(m[1]); // Integer Number
    if (m = text.match(/^\s*((?:\+|\-)?\d*\.\d*)\s*,?$/)) return parseFloat(m[1]); // Floating Number
    if (m = text.match(/^\s*(.*?)\s*,?$/)) return m[1]; // Unquoted Text
    return text;
  } );
}

let data = `"This is\, a value",Hello,4,-123,3.1415,'This is also\, possible',true`;
let obj = parseCSVLine(data);
console.log( JSON.stringify( obj, undefined, 2 ) );