如何使用jquery创建这些嵌套的dom元素？

var $container = $('<div class="container"><div class="row"><div class="col-md-6"><h1>Hello World!</h1></div></div></div>');

var $container = $('<div class="container"></div>');
var $row = $('<div class="row"></div>');
var $col = $('<div class="col-md-6"></div>');
var $h1 = $('<h1>Hello World!</h1>');

$col.append($h1);
$row.append($col);
$container.append($row);

var $container = $('<div class="container"></div>');
var $row = $('<div class="row"></div>');
var $col = $('<div class="col-md-6"></div>');
var $h1 = $('<h1>Hello World!</h1>');

$col.html($h1);
$row.html($col);
$container.html($row);

var $container = $('<div class="container"></div>');
var $row = $('<div class="row"></div>');
var $col = $('<div class="col-md-6"></div>');
var $h1 = $('<h1>Hello World!</h1>');

$h1.appendTo($col);
$col.appendTo($row);
$row.appendTo($container);