# How to check a Point don’t have NaN as parameter in java

I created a point class in Java:

```public class Point {
private final float THRESHOLD = (float) 0.0001;
private final float x;
private final float y;

//getter
public float getX(){return x;}
public float getY(){return y;}

//constructor
public Point(float x,float y){this.x = x;this.y = y;}

//equals
public boolean equals(Object p1) {
if (p1 != null && p1.getClass() == getClass()) {return (Float.floatToIntBits(x) == Float.floatToIntBits(((Point) p1).x))
||(Float.floatToIntBits(y) == Float.floatToIntBits(((Point) p1).y)
||Math.abs(x - ((Point) p1).x) < THRESHOLD && Math.abs(y - ((Point) p1).y) < THRESHOLD);}
return false;
}

//toString
public String toString() {
return "x=" + x + " y=" + y;
}
}
```

Then I created a rectangle class using the two points as topLeft and bottomright:

```public final class Rectangle {

private final Point topLeft;
private final Point bottomRight;

//getters
public Point getbottomRight() {return bottomRight;}

//constructor
Rectangle(Point topLeft,Point bottomRight){this.topLeft = topLeft; this.bottomRight = bottomRight;}
Rectangle(float topLeftX,float topLeftY,float bottomRightX, float bottomRightY){
this(new Point(topLeftX,topLeftY),new Point(bottomRightX,bottomRightY));
}

//equals
public boolean equals(Object r1) {
if (((Rectangle)r1).bottomRight == this.bottomRight &&
((Rectangle)r1).topLeft == this.topLeft &&
r1.getClass() == getClass()) {return true;}
return false;
}

//toString
public String toString() {
return "topLeft: " + topLeft + " bottomRight" + bottomRight;
}

//computeArea
public float computeArea() {
return Math.abs(
(topLeft.getX() - bottomRight.getX())*(bottomRight.getY() - topLeft.getY()));
}
}
```

However, we all know when one parameter in point equal to NaN, the rectange should not work(like throw errors), how to design it? Thanks.

You can use the `Float.isNan` method:

```Rectangle(Point topLeft, Point bottomRight){
if (Float.isNan(topLeft.getX()) || Float.isNan(topLeft.getY()) ||
Float.isNan(bottomRight.getX()) || Float.isNan(bottomRight.getY())) {
throw new IllegalArgumentException("Point contains non-numeric coordinate");
}
this.topLeft = topLeft;
this.bottomRight = bottomRight;
}
```

Alternatively, you can encapsulate this check in the `Point` class by adding a method that will only return `true` if both coordinates are not NaN. You would then be able to call that method on both points in the `Rectangle` constructor.

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