OOP example

OOP.java

package oop;

public class OOP {
    
    public static void main(String[] args) {
        Pants pants = new Pants("dark blue");
        System.out.println("I have a pair of " + pants.getColour() + " pants!");
        pants.setColour("vermilion");
        System.out.println("Now my pants are " + pants.getColour() + ", and it's much better!");
    }
}

Output

I have a pair of dark blue pants!
Now my pants are vermilion, and it's much better!

Pants.java

package oop;

// A class modelizing pants
public class Pants {
    
    // It has a colour
    private String colour;

    // initialColour being the colour we want when we create a new instance
    public Pants(String initialColour) {
        // i could also write colour = initialColour;
        this.colour = initialColour;
    }

    public String getColour() {
        return this.colour;
    }

    public void setColour(String colour) {
        this.colour = colour;
    }

    @Override
    public String toString() {
        return "Pants{" + "colour=" + colour + '}';
    }
}