Why Wordpress AJAX returns undefined however it works fine when I add static url instead of dynamic function?

Question

Code from functions.php

function university_files()
{
   wp_localize_script('main-university-js', 'universityData', array(
        'root-url' => get_site_url()
    ));
};

add_action('wp_enqueue_scripts', 'university_files');

Code from JS

getResults() {
    $.getJSON(
      universityData.root_url +
        "/wp-json/wp/v2/posts?search=" +
        this.searchField.val(),
      (posts) => {
        this.resultsDiv.html(`
        <h2 class ="search-overlay__section-title">General Information</h2>
          ${
            posts.length
              ? `<ul class="link-list min-list">`
              : `No General Information Marched your search`
          }
            ${posts
              .map(
                (item) =>
                  `<li><a href="${item.link}">${item.title.rendered}</a></li>`
              )
              .join("")}
          ${posts.length ? `</ul>` : ""}
        
        `);
        this.isSpinnerVisible = false;
      }
    );
  }

Answer 1

Because you have:

universityData.root_url

But you localised:

'root-url' => get_site_url()

root_url != root-url