How do I see if two rectangles intersect in JavaScript or pseudocode?

Question

I have two rectangles which I must return in a function whether they intersect or not.

They are represented by [ x0, y0, x1, y1 ] pairs that represent the t

Answer 1

Check for the cases where the rectangles are definitely not intersecting. If none of these cases are true then the rectangles must intersect. i.e.:

public boolean rectanglesIntersect( 
    float minAx, float minAy, float maxAx, float maxAy,
    float minBx, float minBy, float maxBx, float maxBy ) {
    boolean aLeftOfB = maxAx < minBx;
    boolean aRightOfB = minAx > maxBx;
    boolean aAboveB = minAy > maxBy;
    boolean aBelowB = maxAy < minBy;

    return !( aLeftOfB || aRightOfB || aAboveB || aBelowB );
}

This illustrates the concept but could be made slightly faster by inlining the booleans so as to take advantage of the short-circuiting behavior of ||