Collision detection between two rectangles in java

Question

I have two rectangles, the red rectangle (can move) and the blue rectangle. Both have: x, y, width, height.

How can I say in a programming language such as Java when

Answer 1

In java , to detect if two when two rectangles collide, you can use intersects() method

Sample Code:

Rectangle r1 = new Rectangle(x1,y1,x2,y2);
Rectangle r2 = new Rectangle(x1,y1,x2,y2);
if(r1.intersects(r2))
{
    //what to happen when collision occurs goes here
}