Chestnut:
stop the button being called more than once within 1 second; first, the result of my baidu

btn.onclick = function add(){
    btn.innerHTML = Number(btn.innerHTML) + 1;    
    btn.onclick = null;
    clearTimeout(timer);
    var timer = setTimeout(function(){
        btn.onclick = add;
    },1000);    
}

btn.onclick = (function(){
    var last = Date.now();
    return function(){
        var now = Date.now();
        if((now - last)>1000){
            btn.innerHTML= Number(btn.innerHTML) + 1;            
        }
        last = now;
    }
})();

both of the above methods can be implemented, and the question that puzzles me at present is:
1-is there a better way to use timers or closures;
2-if not, which of the above two methods is more suitable for component-based public use?

there are many places that need to be used in the current project, so I would like to try to encapsulate a simple public method myself, which can support click events to prevent multiple calls within 1 second, or custom extensions (later).

the project is based on angular4.x (no similar method for deferring execution has been found.), of course, native js is completely OK