Collection data output behavior

838385

Hi, I am working on a sumo project. I am using TraCI 4J to control the simulation. I am stuck in a simple problem:

for (int i = 0; i < 37260; i++) {

     Collection<Vehicle> vehicles = conn.getVehicleRepository().getAll().values();

     Iterator<Vehicle> itr = vehicles.iterator();

     while (itr.hasNext()) {

             Vehicle vehicle = itr.next();

                        if(vehicle.getType()=="typeNS")

                                System.out.println("Found typeNS");

                       if(vehicle.getType()=="typeWE")

                                System.out.println("Found typeWE");

 

 

  System.out.println(vehicle.getType());

    }

}

The last output gives every possible vehicle.getType but the top if statement always get ommitted. There are hundres of typeNS and typeWE but it does not catch that. Any idea? What's the problem here?

Unknown

                        if(vehicle.getType()=="typeNS")
. . .
                       if(vehicle.getType()=="typeWE")
The last output gives every possible vehicle.getType but the top if statement always get ommitted. There are hundres of typeNS and typeWE but it does not catch that. Any idea? What's the problem here?

You are comparing 'objects' and the objects are NOT equal to each other - they are DIFFERENT objects.

Use the equalsIgnoreCase' method of String to compare strings.

https://docs.oracle.com/javase/7/docs/api/java/lang/String.html#equalsIgnoreCase%28java.lang.String%29

public boolean equalsIgnoreCase(String anotherString)

Compares this String

to another String

, ignoring case considerations. Two strings are considered equal ignoring case if they are of the same length and corresponding characters in the two strings are equal ignoring case.

The Java Tutorials has trails that show how to compare strings:

https://docs.oracle.com/javase/tutorial/java/data/comparestrings.html