How to clear all <div>s’ contents inside a parent <div>?

jQuery's empty() function does just that:

$('#masterdiv').empty();

clears the master div.

$('#masterdiv div').empty();

clears all the child divs, but leaves the master intact.

jQuery('#masterdiv div').html('');

Use jQuery's CSS selector syntax to select all div elements inside the element with id masterdiv. Then call empty() to clear the contents.

$('#masterdiv div').empty();

Using text('') or html('') will cause some string parsing to take place, which generally is a bad idea when working with the DOM. Try and use DOM manipulation methods that do not involve string representations of DOM objects wherever possible.