How can I parse a string with a comma thousand separator to a number?

Question

I have 2,299.00 as a string and I am trying to parse it to a number. I tried using parseFloat, which results in 2. I guess the comma is the problem

Answer 1

With this function you will be able to format values in multiple formats like 1.234,56 and 1,234.56, and even with errors like 1.234.56 and 1,234,56

/**
 * @param {string} value: value to convert
 * @param {bool} coerce: force float return or NaN
 */
function parseFloatFromString(value, coerce) {
    value = String(value).trim();

    if ('' === value) {
        return value;
    }

    // check if the string can be converted to float as-is
    var parsed = parseFloat(value);
    if (String(parsed) === value) {
        return fixDecimals(parsed, 2);
    }

    // replace arabic numbers by latin
    value = value
    // arabic
    .replace(/[\u0660-\u0669]/g, function(d) {
        return d.charCodeAt(0) - 1632;
    })

    // persian
    .replace(/[\u06F0-\u06F9]/g, function(d) {
        return d.charCodeAt(0) - 1776;
    });

    // remove all non-digit characters
    var split = value.split(/[^\dE-]+/);

    if (1 === split.length) {
        // there's no decimal part
        return fixDecimals(parseFloat(value), 2);
    }

    for (var i = 0; i < split.length; i++) {
        if ('' === split[i]) {
            return coerce ? fixDecimals(parseFloat(0), 2) : NaN;
        }
    }

    // use the last part as decimal
    var decimal = split.pop();

    // reconstruct the number using dot as decimal separator
    return fixDecimals(parseFloat(split.join('') +  '.' + decimal), 2);
}

function fixDecimals(num, precision) {
    return (Math.floor(num * 100) / 100).toFixed(precision);
}

parseFloatFromString('1.234,56')
"1234.56"
parseFloatFromString('1,234.56')
"1234.56"
parseFloatFromString('1.234.56')
"1234.56"
parseFloatFromString('1,234,56')
"1234.56"