javascript - How to open set this to any object in jquery? -

if have function this

function foo(a) {     $(this).html(a); }  var r = $("#hello");

and can't change function foo, can call foo using r, such inside foo, this refer object selected r?

i tried this

r.each(function(i, x) {     foo(1); });

but did not work. this referred window object.

that's because when call function itself, this set global object (or undefined) unless function scope bound.

to use function way wanted, write this:

r.each(foo);

that pass function directly , ensure this set same value if body of foo inside of anonymous function.

if want pass additional parameters foo not passed each, have call using call or apply:

r.each(function() {   foo.call(this, 1); });

Tomorrow