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iOS Object-Oriented Swift 2.0 Complex Data Structures Methods

Hunter Hayes
Hunter Hayes
1,415 Points
Posted by Hunter Hayes
Hunter Hayes
1,415 Points

Why does the for in loop go from x-range...x+range; and similarly for y-range...y+range? This is a little unclear.

I don't understand the meaning behind the x-range and x+range? Can you clear this up for me. I am a bit confused. Thank you for your help!

4 Answers

Damien Watson
Damien Watson
27,419 Points
Damien Watson
Damien Watson
27,419 Points

I'll have a crack at explaining this:

The point(x,y) is where the cannon is located on a grid and the range is how far around this point the cannon can shoot.

Assuming that range=1, the cannon can shoot 1 block to the left of its position (-1) and 1 block to its right (+1).

To calculate this, it would be from cannon.x-1 to cannon.x+1 or x-range to x+range. Breaking it down into how the for loop works it would look like something like this:

let range = 1
let cannon = Point( x:4, y:2 )

for (xCoord in (x-range)...(x+range) {}
// is the same as saying

for (xCoord in (4 - 1)...(4 + 1) {}
// loop from x position 3 (left of cannon) to 5 (right of cannon)

The y-range works the same but in the vertical range.

Does this help?

Yusuf Akbar
Yusuf Akbar
2,457 Points
Yusuf Akbar
Yusuf Akbar
2,457 Points

Yes, helps a lot.

Thanks mate :)

prakash Bhise
PLUS
prakash Bhise
Courses Plus Student 61 Points
prakash Bhise
prakash Bhise
Courses Plus Student 61 Points

it helped me to thank you