How to use

eq

function

in

Array

// [Yihui] Scroll the chapter body to the i-th highlighted string
  function scrollToHighlighted(d) {
   var n = $highlighted.length;
   hi = hi === undefined ? 0 : hi + d;
   // navignate to the previous/next page in the search results if reached the top/bottom
   var b = hi < 0;
   if (d !== 0 && (b || hi >= n)) {
    var path = currentPath(), n2 = toc_visible.length;
    if (n2 === 0) return;
    for (var i = b ? 0 : n2; (b && i < n2) || (!b && i >= 0); i += b ? 1 : -1) {
     if (toc_visible.eq(i).data('path') === path) break;
    }
    i += b ? -1 : 1;
    if (i < 0) i = n2 - 1;
    if (i >= n2) i = 0;
    var lnk = toc_visible.eq(i).find('a[href$=".html"]');
    if (lnk.length) lnk[0].click();
    return;
   }
   if (n === 0) return;
   var $p = $highlighted.eq(hi);
   $p[0].scrollIntoView();
   $highlighted.css('background-color', '');
   // an orange background color on the current item and removed later
   $p.css('background-color', 'orange');
   setTimeout(function() {
    $p.css('background-color', '');
   }, 2000);
  }