Bool type and logical operators in Swift - Time & Space Complexity
When using Bool values and logical operators, it is important to see how the number of operations changes as we combine more conditions.
We want to know how the time to evaluate these expressions grows when we add more logical checks.
Analyze the time complexity of the following code snippet.
func checkAllTrue(values: [Bool]) -> Bool {
for value in values {
if !value {
return false
}
}
return true
}
This function checks if all Boolean values in an array are true by scanning each one until it finds a false.
Identify the loops, recursion, array traversals that repeat.
- Primary operation: Looping through each Boolean in the array.
- How many times: Up to once per element, stopping early if a false is found.
As the number of Booleans increases, the function may check more values, but it can stop early if a false appears.
| Input Size (n) | Approx. Operations |
|---|---|
| 10 | Up to 10 checks |
| 100 | Up to 100 checks |
| 1000 | Up to 1000 checks |
Pattern observation: The number of checks grows roughly in direct proportion to the number of values, but can be less if a false is found early.
Time Complexity: O(n)
This means the time to check all values grows linearly with the number of Booleans in the array.
[X] Wrong: "Logical operators always take constant time regardless of input size."
[OK] Correct: When used in a loop over many values, the total time depends on how many values are checked, so it grows with input size.
Understanding how logical checks scale helps you write efficient conditions and shows you can think about how code runs as data grows.
What if we changed the function to check if any value is true instead of all? How would the time complexity change?