How to set style on selection of vector layer in Open layer 3?

Question

I just drawn a polygon and modifying it. How to set style on selection of polygon in Open layer 3

thanks

Answer 1

var selectClick = new ol.interaction.Select();
map.addInteraction(selectClick);
var sf =selectClick.getFeatures();
sf.on('add', addSelectionListener);
sf.on('remove', removeSelectionListener);

function addSelectionListener(){
var sf = selectClick.getFeatures(); 
sf.forEach(function(feature){
feature.setStyle(styles);
}); 
}
function removeSelectionListener(){
var sf = source.getFeatures();
sf.forEach(function(feature){
feature.setStyle(null);
}); 
}