Swift Tutorial - Swift Tuples

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 rectangle1.

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

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 underscore _.

So, if you needed only the x origin for the rectangle, you could do as follows.

var (e, _, _, _) = rectangle2

You can assign tuple values to either constants or variables.