Sometimes, we want to convert a JavaScript object to a query string.

In this article, we’ll look at how to convert a JavaScript object to a query string.

How to convert a JavaScript object to a query string?

To convert a JavaScript object to a query string, we can use the Object.entries method and some array methods.

For instance, we write:

const obj = {
  foo: "22",
  bar: "23434"
};

const queryString = Object.entries(obj)
  .map(([key, value]) => {
    return `${encodeURIComponent(key)}=${encodeURIComponent(value)}`;
  })
  .join('&')
console.log(queryString)

to call Object.entries with obj to convert obj to an array of key-value pair arrays.

Then we call map with a callback to combine the key and value into a query parameter string.

Next, we call join with '&' to join the query parameters together.

As a result, queryString is 'foo=22&bar=23434'.

Conclusion

To convert a JavaScript object to a query string, we can use the Object.entries method and some array methods.