sharepoint online – How to get web scope feature GUID?

In JSOM API SP.Feature object exposes the following properties:

• DefinitionId – specifies the identifier for this feature
• DisplayName

The following example shows how to find a feature by DisplayName property and print its identifier:

Example

  var featureTitle = "TeamCollab";   //"Team Collaboration Lists"; 

  var ctx = SP.ClientContext.get_current();
  var features = ctx.get_web().get_features();
  ctx.load(features,'Include(DisplayName,DefinitionId)'); 
  ctx.executeQueryAsync(
     function(){

        var result = features.get_data().filter(function(f){
            //console.log(f.get_displayName()); 
            if(f.get_displayName() == featureTitle)
               return f;    
        });

        //print results
        for(var i = 0; i < result.length; i++){
           console.log(result(i).get_definitionId().toString());
        }

     },
     function(sender,args){
        console.log(args.get_message()); 
     });