Swift Double - maximum() Function

---

---

The maximum() function is used to calculate the greatest number among the given numbers. It is a predefined method of Double structure. This method takes two values and compares them with each other just like we do use> sign, e.g. if x > y returns x. In this method, if both the given numbers are NaN(not a number) or any of the numbers are NaN, then this method will return NaN.

For example, we have two numbers: n = 10 and m = 20, now using the maximum(n, m) function we will get the maximum number between n and m which is m = 20.

Syntax

Following is the syntax of the maximum() function −

func maximum(_ X: Double, _ Y: Double)

Parameters

The function takes two Double values (X and Y) to compare.

Return Value

Returns the larger of the two numbers.

Now we will discuss the usage of the maximum() function with the help of the following examples:

Example 1

Swift program to demonstrate the use of maximum() function −

import Foundation

// Double Inputs
let num1 : Double = -42.32323
let num2 : Double = 23.334343
let num3 : Double = Double.nan
let num4 : Double = Double.infinity
let num5 : Double = 1.233
let num6 : Double = -123.233

// Finding maximum numbers 
// Using maximum() function
print("Which is maximum: \(num1) or \(num2) = ", Double.maximum(num1, num2))
print("Which is maximum: \(num2) or \(num3) = ", Double.maximum(num2, num3))
print("Which is maximum: \(num3) or \(num4) = ", Double.maximum(num3, num4))
print("Which is maximum: \(num2) or \(num5) = ", Double.maximum(num2, num5))
print("Which is maximum: \(num1) or \(num6) = ", Double.maximum(num1, num6))

Output

Which is maximum: -42.32323 or 23.334343 =  23.334343
Which is maximum: 23.334343 or nan =  23.334343
Which is maximum: nan or inf =  inf
Which is maximum: 23.334343 or 1.233 =  23.334343
Which is maximum: -42.32323 or -123.233 =  -42.32323

Example 2

Swift program to determine the maximum double number.

import Foundation

// Input 1
let item1 : Double = 34.6565
let item2 : Double = 4.32

// Finding maximum values using maximum() function
if (Double.maximum(item1, item2) == item1) {
   print("Yes! \(item1) is maximum")
} else {
   print("No! \(item1) is not maximum")
}

Output

Yes! 34.6565 is maximum

Example 3

Swift program to remove a maximum element from the given array. Here we find the largest element from the given array using the maximum() function and then remove it with the help of the filter() function.

import Foundation

// Function to remove a maximum element from the given array
func removeMaximumElement(arr: [Double]) -> [Double] {
   if arr.isEmpty {
       print("Array is empty")
   }

   var maxItem = arr[0]
   
   // Calculating maximum element
   for x in arr {
      if Double.maximum(x, maxItem) == x {
         maxItem = x
      }
   }
   
   // Removing the maximum element
   let result = arr.filter { $0 != maxItem }
   return result
}

// Input array
let numbers = [4.2, 83.3, 2.3, 1.0, 532.223]
print("Array before removing maximum element:", numbers)
print("Array after removing maximum element:", removeMaximumElement(arr: numbers))

Output

Array before removing maximum element: [4.2, 83.3, 2.3, 1.0, 532.223]
Array after removing maximum element: [4.2, 83.3, 2.3, 1.0]

Example 4

Swift program to find the maximum element from the given array and then calculate the square of that element. Here using the maximum() function we calculate the largest element present in the array after that we calculate its square using maxItem * maxItem.

import Foundation

// Function to find the square of the maximum element
func squareOfMaximumElement(arr: [Double]) -> Double {
   if arr.isEmpty {
        print("Array is empty")
    }

    var maxItem = arr[0]
    
    // Calculating maximum element
    for x in arr {
        if Double.maximum(x, maxItem) == x {
            maxItem = x
        }
    }
    
    //  Square of maximum element
    let result = maxItem * maxItem
    return result
}

// Input array
let numbers = [3.4, 12.3, 66.4, 2.1]
print("Square of maximum element is:", squareOfMaximumElement(arr: numbers))

Output

Square of maximum element is: 4408.960000000001