Loop through string array with exit if test passed
Join the string to create a jQuery selector

var elementTypes = ['btn', 'textbox', 'ui-jqgrid', 'flexboxdiv', 'headerlabel'];
var selector = '.' + elementTypes.join(', .');

return $('.TestModule').first().find(selector).length &gt; 0;


The variable selector will return the string '.btn, .textbox, .ui-jqgrid, .flexboxdiv, .headerlabel' which can be used in the jQuery selector.

The statement

return $('.TestModule').first().find(selector).length &gt; 0;


is equivalent to 

return $('.TestModule').first().find('.btn, .textbox, .ui-jqgrid, .flexboxdiv, .headerlabel').length &gt; 0;


after the string substitution.



To make it more dynamic, store complete selector in the array and join the array by ,-comma.

var elementTypes = ['.btn', '.textbox', '.ui-jqgrid', '.flexboxdiv', '.headerlabel', '#myId', 'input', 'input[name="firstname"]'];
var selector = elementTypes.join(', ');