Tuples are ordered lists of values.
In Swift, you can group related elements together as a tuple, reducing the need to depend on complex types, objects, and immutable arrays.
The following code shows how you would declare a tuple for a rectangle.
let rectangle1 = (0, 0, 200, 100)
The code above uses the
let keyword to declare a constant and give the
constant the name
After the assignment operator
=, you supply
a comma-separated list of values enclosed in parentheses.
The value of rectangle1 would be (0, 0, 200, 100) .
For greater clarity, you can annotate each value in the tuple list as shown in the following code.
var rectangle2 = (x:0, y:0, width:200, height:100)
To pull an individual value out of a tuple, decompose the values and assign them to a constant.
let (a, b, c, d) = rectangle1 println(c)
To decompose your tuple values, you can use the
let keyword followed by
a comma-separated list of variable names.
Each name will be filled with the corresponding value from the tuple.
You can now use these variables as usual.
To ignore some values in a tuple, replace a variable name with an
So, if you needed only the
x origin for the rectangle,
you could do as follows.
var (e, _, _, _) = rectangle2 print(e)
You can assign tuple values to either constants or variables.