The .toggle() method is provided for convenience. It is relatively straightforward to implement the same behavior by hand, and this can be necessary if the assumptions built into .toggle() prove limiting.
For example, .toggle() is not guaranteed to work correctly if applied twice to the same element.
Since .toggle() internally uses a click handler to do its work, we must unbind click to remove a behavior attached with .toggle(), so other click handlers can be caught in the crossfire.
The implementation also calls .preventDefault() on the event, so links will not be followed and buttons will not be clicked if .toggle() has been called on the element.
This is the "click an element to run the specified functions" signature of .toggle(). It should not be confused with the "change the visibility of an element" of .toggle() which is not deprecated. The former is being removed to reduce confusion and improve the potential for modularity in the library. The jQuery Migrate plugin can be used to restore the functionality.