TheDeveloperBlog.com
C-Sharp | Java | Python | Swift | GO | WPF | Ruby | Scala | F# | JavaScript | SQL | PHP | Angular | HTML
Swift Odd and Even Numbers
Find odd and even numbers with modulo division. Handle negative numbers.Odd, even. The parity of a number is sometimes important. 0 is even. 1 is odd. With odd and even checks, we can alternate a test or computation in a loop.
With modulo division in Swift, we can tell the parity of a number. If a modulo division by 2 returns 0, we have an even number. If it does not, we have an odd.
Even. Let us begin with the even() func. This returns a bool indicating whether the number is even. It returns the result of an expression—whether the number is evenly divisible by 2.
For: We use a for-loop over the numbers 0 through 5 inclusive. We test whether these numbers are even and print the results.
Note: Negative numbers are correctly supported here. A negative number can be evenly divisible by 2.
Swift program that finds even numbers
func even(number: Int) -> Bool {
// Return true if number is evenly divisible by 2.
return number % 2 == 0
}
// Test the parity of these numbers.
for i in 0...5 {
let result = even(i)
// Display result.
print("\(i) = \(result)")
}
Output
0 = true
1 = false
2 = true
3 = false
4 = true
5 = false
Odd. An odd number is not even. It can be negative. Here we test for "not equal to zero." We do not test for a remainder of 1, as this would not support negative numbers.
Swift program that finds odd numbers
func odd(number: Int) -> Bool {
// Divide number by 2.
// ... If remainder is 1, we have a positive odd number.
// ... If remainder is -1, it is odd and negative.
// ... Same as "not even."
return number % 2 != 0
}
for i in -3...3 {
let result = odd(i)
print("\(i) = \(result)")
}
Output
-3 = true
-2 = false
-1 = true
0 = false
1 = true
2 = false
3 = true
A summary. Usually the parity of a number is not directly needed. But with even() and odd() we can test for even numbers and odd ones to change how we handle values in a loop.
© TheDeveloperBlog.com
The Dev Codes
Related Links:
- Swift String Append Example: reserveCapacity
- Swift File (Read Text File Into String)
- Swift Find Strings: range of Example
- Swift Subscript Example
- Swift hasPrefix and hasSuffix Examples
- Swift Array of Dictionary Elements
- Swift Tutorial
- Swift Odd and Even Numbers
- Swift Operator: Equality, Prefix and Postfix
- Swift Dictionary Examples
- Swift Class Example: init, self
- Swift Combine Arrays: append, contentsOf
- Swift Initialize Array
- Swift Int Examples: Int.max, Int.min
- Swift 2D Array Examples
- Swift Error Handling: try, catch
- Swift Repeat While Loop
- Swift Optional: Nil Examples
- Swift Replace String Example
- Swift Print: Lines, Separator and Terminator
- Swift inout Keyword: Func Example
- Swift Lower, Uppercase and Capitalized Strings
- Swift enum Examples: case, rawValue
- Swift Padding String Example (toLength)
- Swift UIActivityIndicatorView Example
- Swift UIAlertController: Message Box, Dialog Example
- Swift UIButton, iOS Example
- Swift UICollectionView Tutorial
- Swift UIColor iOS Example: backgroundColor, textColor
- Swift UIFont Example: Name and Size
- Swift UIImageView Example
- Swift UIKit (Index)
- Swift UILabel Tutorial: iPhone App, Uses ViewController
- Swift String
- Swift Remove Duplicates From Array
- Swift If, If Else Example
- Swift Caesar Cipher
- Swift UIStepper Usage
- Swift UISwitch: ViewController
- Swift UITableView Example: UITableViewDataSource
- Swift UITextField: iPhone Text Field Example
- Swift UITextView Example
- Swift UIToolbar Tutorial: UIBarButtonItem
- Swift UIWebView: LoadHtmlString Example
- Swift Var Versus Let Keywords
- Swift Math: abs, sqrt and pow
- Swift Reverse String
- Swift Struct (Class Versus Struct)
- Top 22 Swift Interview Questions (2021)
- Swift Substring Examples
- Swift Switch Statements
- Swift Convert Int to Character: UnicodeScalar, utf8
- Swift Property Examples
- Swift isEmpty String (characters.count Is Zero)
- Swift Recursion
- Swift ROT13 Func
- Swift Convert String to Byte Array: utf8 and UInt8
- Swift Keywords
- Swift Convert String to Int Example
- Swift Join Strings: joined, separator Examples
- Swift String Literal, Interpolation
- Swift Extension Methods: String, Int Extensions
- Swift Characters: String Examples
- Swift Func Examples: Var, Return and Static
- Swift Guard Example: Guard Else, Return
- Swift Fibonacci Numbers
- Swift Trim Strings
- Swift Set Collection: Insert and Contains
- Swift Tuple Examples
- Swift Loops: for, repeat and while Examples
- Swift Split Strings Example (components)
- Swift Array Examples, String Arrays
- Swift UIPickerView Example: UIPickerViewDataSource
- Swift UIProgressView Example: Progress
- Swift UISegmentedControl
- Swift UISlider Example
- Swift Random Numbers: arc4random
- Swift ASCII Table
- Swift Range Examples (index, offsetBy)
- Swift String Length
- Swift Sort String Arrays: Closure Examples