how to push arrays in array and NOT concatenate?

Question

I have the following php code that gives an array variable called "markers".

window.markers = [];

<?php if( have_rows('actin_center') ): ?>
<?php while( have_rows('actin_center') ): the_row(); ?>

window.markers.push( [ ['<?php the_sub_field('center_name'); ?>', '<?php the_sub_field('center_address'); ?>', <?php the_sub_field('latitude'); ?>, <?php the_sub_field('longitude'); ?>] ] );

<?php endwhile; ?>
<?php endif; ?>

This works fine so far yet returns the array (on alert) as:

Cool center 1,Rewitz Gofella, 1234 Lorem,50,50,Cool center 2,Lorem Ipsum, 1234 Quosque,60,60,Cool center 3,Veniat elaborat, 1234 Ipsum,70,70

What I need, yet, is the following form keeping the arrays (of sub_fields) as they originally are inside the array and NOT concatenate them. As:

var markers = [
    ['First Center','First Address',50,50],
    ['Second Center','Second Address', -25.363882,131.044922],
    ['Third Center','Third Address', 10.363882,95],
    ['Fourth Center','Fourth Address', -50,-90],
    ['Fifth Center','Fifth Address', 30,5],
];

As you can see in the code above I tried with the simple double bracket [[ ]] but this doesn't work. How is this to be done correctly? Thanks so much for help.

PS: If someone feels urged to down vote my question, please be so kind to let me know why so I may learn something.

Answer 1

Due to comments:
alert( [[1,2][3,4]] ) will popup wrong 1,2,3,4
alert( JSON.stringify([[1,2][3,4]]) will popup [[1,2],[3,4]]

.push([1,2]) will add an array to markers : [[1,2],[3,4],[5,6]]
.push(1,2) will add elements to markers : [1,2,3,4,5,6]

But better way, is don't execute javascript .push (save client CPU time)
Define array in javascript in this way:

window.markers = [
<?php while( have_rows('actin_center') ): the_row(); ?>
  ["<?php the_sub_field('center_name');?>","<?php the_sub_field('center_address'); ?>",<?php the_sub_field('latitude');?>, <?php the_sub_field('longitude');?>],
<?php endwhile; ?>
];

result should looks like this

window.markers = [
['First Center', 'First Address', 50, 50],
['Second Center','Second Address',-25.363882, 131.044922],
[... ,... , ... ,...],
];