String.compareTo method to compare [closed]

Question

I'm pretty new to java and don't really know about these stuff and it's my first time writing these methods! of course I have no clue how I can write them.

will you check my Method and let me know what i'm doing wrong? thank you.

public static void sortByVehicleMakeModel(Vehicle[] vehicles) {
    boolean swapped = true;

    for(int y = 0; y < vehicles.length && swapped; y++) {
        swapped=false;
        for(int x = 0; x < vehicles.length - (y+1); x++) {
            if(vehicles[x].getMake() && vehicles[x].getModel().compareTo(vehicles[x + 1].getMake() && vehicles[x].getModel())) {    
                swap(vehicles, x, x + 1);
                swapped=true;
            }
        }
    }
}

My error is on the second statemnet .compareto() The operator && is undefined for the argument type(s) java.lang.String, java.lang.String

Answer 1

There are probably better approaches as my knowledge Java is a bit limited but have you considered the Array.sort implementation?

Using that you might do something like:

public void sortByVehicleMakeModel(Vehicle[] vehicles) {  
    Arrays.sort(vehicles, new VehicleComparator());
}

class VehicleComparator implements Comparator<Vehicle> {

    public int compare(Vehicle v1, Vehicle v2) {
         return getMakeModel(v1).compareTo(getMakeModel(v2));
    }

    private String getMakeModel(Vehicle v) {
        return v.getMake() + v.getModel();
    }
}