how to choose only first "if" to set marker visible true in javascript

i have a code to filtering marker to show in map

if(marker.session == session || session.length === 0) {
               if (marker.category == str || $("#type").length === 0){
                   marker.setVisible(true); 

                   console.log("log2sessionbasedonfilter1"+session);
               }
           } 

i just want to make this code work if i only use first "if" fuction and make marker visible.

how to take only one "if" function from that function.

please help me, im in my learn.

thanks in advanced.

-kraken.