3 Assignment Operator in Swift
The assignment operator (a = b) initializes or updates the value of a with the value of b:
let b = 10
var a = 5
a = b
// a is now equal to 10
If the right side of the assignment is a tuple with multiple values, its elements can be decomposed into multiple constants or variables at once:
let (x, y) = (1, 2)
// x is equal to 1, and y is equal to 2
Unlike the assignment operator in C and Objective-C, the assignment operator in Swift doesn’t itself return a value. The following statement isn’t valid:
if x = y {
// This isn't valid, because x = y doesn't return a value.
}
This feature prevents the assignment operator (=) from being used by accident when the equal to operator (==) is actually intended. By making if x = y invalid, Swift helps you to avoid these kinds of errors in your code.
https://docs.swift.org/swift-book/Lan...