I have a class named Time with attributes Hour, Min and Sec:

class Time {
  private int Hour;
  private int Min;
  private int Sec;
}

a constructor:

public Time(int h, int m, int s){
    Hour = h;
    Min = m;
    Sec = s;
}

and an instance time1 of the Time class:

Time time1 = new Time(12, 34, 52);

I wanted to create a method inside that will sum to the Hour attribute of time1 instance and return me the result in Time type, but when I try this it gives me the "Type mismatch: cannot convert from int to Time" error:

     public Time Add(int hrs){
     return Hour   hrs;
 }

what am I doing wrong here?

CodePudding user response：

You need to instanciate a new Time object

public Time Add(int hrs){
    return new Time(this.Hour   hrs, this.Min, this.Sec);
}

Also java naming convention, is lowerCamelCase for methods and attributs so hour, min, sec and add

CodePudding user response：

You seem to be looking for an instance method in Time class however, implementations may vary:

• Mutate inner state of Time instance -- similar to a setter, returning reference to this

// mutate current instance:
class Time {
    public Time addHours(int hours) {
        this.Hours  = hours;
        return this;
    }
}

Usage:
Time time1 = new Time(12, 34, 52);
time1.addHours(2); // time1.Hour becomes 14

• Immutable implementation -- create new instance of time using its Hour and hours

// mutate current instance:
class Time {
    public Time addHours(int hours) {
        return new Time(Hour   hours, Min, Sec);
    }
}

// Usage:
Time time1 = new Time(12, 34, 52);
Time time2 = time1.addHours(2); // time1.Hour remains 14

CodePudding user response：

In the method return type you put Time but you are returning Hour(Type=int) hrs(Type=int) which is their sum and it is also of type int. That's why you are getting the Type mismatch error