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# Can anyone help me understand the code, i have some doubts in the code. What is q1 in the first place.

Through string Interpolation the value of q1 is (1,4) but when i ask the value of q1 at the end of the switch statement it shows an error saying "use of unresolved identifier q1".

let point = (x :1 , y: 4)

switch point {

case let q1 where (point.x > 0) && (point.y > 0): print(" (q1) is in quadrant 1")

default: break

} Hey Devansh,

It is missing the backslash of the string interpolation. Try this:

```let point = (x :1 , y: 4)
switch point {
case let q1 where (point.x > 0) && (point.y > 0): print(" \(q1) is in quadrant 1") // I added this
default: break
}
```

q1 in this case is a constant declared inside switch (case let q1).

So, the code has a constant called point that has this value (x :1 , y: 4) . When you switch point, you are trying to discover if this point is in quadrant 1 (Math concept. All numbers greater than 0 are in quadrant 1).

You can read the code like this: case point.x is greater than 0 and point.y is greater than 0 so assign those values to the constant q1. After that you use the method print to print the value of q1.