Question

I cannot figure out how to prove an existence is true or not;

static boolean existsx(double p1x, double p2x,double[] varray) {
    boolean foundx = false;
    int i;
    //System.out.println(varray.length);

    for (double v : varray){
      if ( varray[i] > p1x &&  v < p2x) {
            foundx = true;
            //System.out.println(x+" was found to be between"+p1x+" and "+p2x);
            break;
       }
       else {
          foundx = false;
       }
    }
    return foundx;
} 

I’m trying to check for an existence of a number in an array between p1x and p2x. If it is true then, return true, else return false.

Answer 1

I think you have a few logical issues, declaring the variable i without ever initializing it being one of them.

The following code should tell you if one of the numbers in the given array is in between those two:

static boolean existsx(double p1x, double p2x,double[] varray){
    double upperBound = Math.max(p1x, p2x);
    double lowerBound = Math.min(p1x, p2x);

    for (double number : varray)
    {
       if ( (number <= upperBound) && (number >= lowerBound))
       {
           return true;
       }
    }

    return false;
}