Exams - Query Strings Mess / Link Strings

/* The input is passed as array of query strings.
 For each field of the form, the query string contains a pair field=value.
 Within each pair, the field name and value are separated by an equals sign, '='.
 The series of pairs are separated by the ampersand, '&’.
 The question mark is used as a separator and is not part of the query string.
 SPACE is encoded as '+' or "%20". URL query string may contain another URL as value.
 Print at single line each processed string as follows:  key=[value]nextkey=[another  value] … etc.
 Multiple whitespace characters should be reduced to one inside value/key names,
 but there shouldn’t be any whitespaces before/after extracted keys and values.
 If a key already exists, the value is added with comma and whitespace after other values
 of the existing key in current string. */

"use strict";

function printArrayOfQueryStrings(args) {
    args.forEach(function(input) {
        var currentLineArr = input.split('&').filter(Boolean);
        var rowQueryObj = {};
        for (var i = 0; i < currentLineArr.length; i += 1) {
            currentLineArr[i] = currentLineArr[i].split('?').filter(Boolean);
            if (currentLineArr[i].length > 1) {
                currentLineArr[i].splice(0, 1);
            }

            currentLineArr[i] = currentLineArr[i][0];

            var pair = currentLineArr[i].split('=').filter(Boolean);
            var field = pair[0].split(/\+|%20/).filter(Boolean);
            field = field.join(' ');

            var value = pair[1].split(/\+|%20/).filter(Boolean);
            value = value.join(' ');

            if (!(field in rowQueryObj)) {
                rowQueryObj[field] = [];
            }

            if (rowQueryObj[field].indexOf(value) < 0) {
                rowQueryObj[field].push(value);
            }
        }

        var resultStr = '';
        for (var key in rowQueryObj) {
            if (rowQueryObj.hasOwnProperty(key)) {
                resultStr += key + '=[' + rowQueryObj[key].join(', ') + ']';
            }
        }

        console.log(resultStr);
    });
}

printArrayOfQueryStrings(['login=student&password=student']);
printArrayOfQueryStrings(['field=value1&field=value2&field=value3',
    'http://example.com/over/there?name=ferret']);
printArrayOfQueryStrings(['foo=%20foo&value=+val&foo+=5+%20+203',
    'foo=%20poo%20&value=valley&dog=wow+',
    'url=https://softuni.bg/trainings/coursesinstances/details/1070',
    'https://softuni.bg/trainings?trainer=nakov&course=oop&course=php']);
printArrayOfQueryStrings(['surprise=box&surprise=pink+ribbon&flowers=red%20roses',
    'day=birthday&day=friday%20&day=sunny+day']);