Swift allows us to combine or chain logical operators, &&, ||, and ! in order to create longer, more complex compound expressions.

Take a look at the following if statement that utilizes the && and || operator in its condition:

let weekday = true 
let dayOff = false 
let weekend = false

if weekday && dayOff || weekend {
  print("Do something fun!") 
} else {
  print("Get some work done") 
}
// Prints: Get some work done

Combining the value of weekday and dayOff with the && operator will result in false. This resulting value is then used to execute the expression false OR weekend which is false. Thus, the entire condition results in false and the second code block is executed.

Note that when chaining Swift’s logical operators, we must keep in mind the order in which execution happens.

The && operator has higher precedence over the || operator.

This rule instructs our program to execute the expression containing the && first, and then use that result to calculate the rest of the expression.

For instance, rearranging the previous condition to…

weekend || weekday && dayOff 

would result in weekday && dayOff still executing first.

Reference this documentation for more information about operator precedence in Swift.