Exceptions

Exceptions

• How does an exception get "thrown"? This is a sketch of what the code of the Color constructor looks like:

     public Color ( int r, int g, int b ) {
  
        if ( r < 0 || r > MAXVALUE )
           throw new IllegalArgumentException("Color value out of range- Red");
        if ( g < 0 || g > MAXVALUE)
           throw new IllegalArgumentException("Color value out of range- Green");
        if ( b < 0 || b > MAXVALUE)
           throw new IllegalArgumentException("Color value out of range- Blue");
  
        this.r = r;
        this.g = g;
        this.b = b;
     }
  

  So the throw keyword is used to accomplish this. The program should construct a new Exception of the appropriate type and throw it. If the code is operating inside of a try statement somewhere, the exception delivered at a matching catch clause if there is one.

Exceptions