Purpose of using arrow function and function keyword syntax together?

Question

First .then method is using arrow function syntax and the second .then method is using the function keyword syntax. Is this just inconsistent coding style or does it have a purpose?

store
      .dispatch(Actions.LOGIN, values)
      .then(() => {
        Swal.fire({
          text: "Sucess!",
          icon: "success",
          buttonsStyling: false,
          confirmButtonText: "Ok!",
          customClass: {
            confirmButton: "btn fw-bold btn-light-primary",
          },
        }).then(function () {
          // Go to page after successfully login
          router.push({ name: "dashboard" });
        });
      })

Answer 1

No, it is not just inconsistency here you can read more.

And some cases you can not use arrow functions.

Also, without a webpack etc or some kind of packager it may not work for all browsers.