The keyword "+" becomes of a CSS selector. It is not a listener to keyboard events (keydown, keypress, and keyup).
In this context, you don’t need a CSS selector to detect key. This magic correspond to an event, and for this reason there is a function that receives the event ...function (event) or function(e). That parameter contains everything that you need.
Now the event identifies the key by property "which" or property "keyCode". Here is a sort of complex, because which and keycode, depends on the browser support.
For now, maybe must check the keydown event on the jQuery page, observe the line 41, and the result when you press a key, specially the keycode and the which attributes.
Finally, the target is detecting the Ctrl key simultaneously with another key. It is important to know it is a special key, and which number must be replaced by ctrlKey and evaluate the number by the property which or keyCode.
jQuery link to keydown and example that make you know what key number (which or keycode) are you press is here.
Your code finally will look like this:
$(document).bind('keydown', function (e) {
if((e.crtlKey && (e.which == 49)) || (e.crtlKey && (e.which == 97))) {
alert('You found the hotkey ctrl+1!');
}
});
The number 49 in the code corresponding to the number ="1" in the alphabetical keyboard part.
The number 97 corresponds to the number ="1" in the numerical keyboard part.