Object to query string

OSCC · JavaScript, Object · Oct 22, 2020

Generates a query string from the key-value pairs of the given object.

  • Use Array.prototype.reduce() on Object.entries() to create the query string from queryParameters.
  • Determine the symbol to be either ? or & based on the length of queryString.
  • Concatenate val to queryString only if it's a string.
  • Return the queryString or an empty string when the queryParameters are falsy.
const objectToQueryString = queryParameters => {
  return queryParameters
    ? Object.entries(queryParameters).reduce(
        (queryString, [key, val], index) => {
          const symbol = queryString.length === 0 ? '?' : '&';
          queryString +=
            typeof val === 'string' ? `${symbol}${key}=${val}` : '';
          return queryString;
        },
        ''
      )
    : '';
};
objectToQueryString({ page: '1', size: '2kg', key: undefined });
// '?page=1&size=2kg'

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