function testCollision(v, index) {
  if (test(p.x, p.y, p.breath, p.length, v.x, v.y, v.radius)) {
    ball.splice(index, 1);
    n--;
    //splice starts deleting the elements of array from the index given in the first parameter
    // and the second parameter accepts the no. of array elements to be deleted
  }
}