Zoom in/out on click in OpenLayers 3?

How to zoom in map in OpenLayerss 3 on click of button?

I want to zoom in and zoom out the map on custom buttons instead of + and - buttons which are on default map.

I tried with:

onclick="map.zoomIn();"

But it's not working, though it was working in OpenLayers 2.

Answer

If you want to zoom in if you click on the map the following should work:

map.on('click', function() {
    map.getView().setZoom(map.getView().getZoom()+1);    

});