how to display index in each jquery code example

Example 1: jquery each

//Array
$.each( arr, function( index, value ){
    sum += value;
});

//Object
$.each( obj, function( key, value ) {
    sum += value;
});

Example 2: foreach jquery

$( "li" ).each(function( index ) {
  console.log( index + ": " + $( this ).text() );
});