var querystring = 'foo=bar&baz=qux&quxx=corge&grault=garply&waldo=fred&plugh=xyzzy' var queryobj = { foo: 'bar', baz: 'qux', quux: 'corge', grault: 'garply', waldo: 'fred', plugh: 'xyzzy' } function encode(data) { let result = '?' for (const key in data) { if (data[key] != null) { result += key + '=' + data[key] + '&' } } return result.slice(0, -1) } function encodeNative(data) { return new URLSearchParams(data).toString() } function buildQueryString(params) { const query = Object.entries(params) .filter(([_, value]) => value !== undefined && value !== null) .map(([key, value]) => `${key}=${encodeURIComponent(String(value))}`) .join('&'); return query ? `?${query}` : ''; } function fastBuildQueryString(params) { let result = '?'; let first = true; for (const key of Object.keys(params)) { const value = params[key]; if (value != null) { if (!first) result += '&'; result += key + '=' + encodeURIComponent(String(value)); first = false; } } return first ? '' : result; } function buildQueryString2(params) { const filteredParams = Object.fromEntries( Object.entries(params).filter(([_, value]) => value != null) ); const query = new URLSearchParams(filteredParams).toString(); return query ? `?${query}` : ''; }