public static void handleNullChecks(){
List<Account> accList = [Select Id, Rating from Account Where Id = '001J400000KjIboIAF'];
if(accList.size() > 0){
System.debug(accList[0]);
}
}
public static void handleBlankScenarios(){
String var1;
String var2;
System.debug(String.isBlank(var1)); //True
System.debug(String.isEmpty(var2)); //True
System.debug(var1 == null); //True
System.debug(var2 == null); // True
var1 = '';
var2 = ' ';
System.debug(String.isBlank(var1)); //True
System.debug(String.isBlank(var2)); //True
System.debug(String.isEmpty(var1)); //True
System.debug(String.isEmpty(var2)); //False
System.debug(var1 == null); //True
System.debug(var2 == null); //True
System.debug(var1 == null); //False
System.debug(var2 == null); // False
}