Swift: Sum an array of integers using reduce

Swift: Sum an Array of Integers Using Reduce

In Swift, the reduce function provides a concise way to combine all elements of an array into a single value. Summing an array of integers is a common use case where reduce can simplify your code by iteratively adding each element to an accumulator.

Code

let numbers = [1, 2, 3, 4, 5]

// Use reduce to sum all elements starting from 0
let sum = numbers.reduce(0) { accumulator, current in
  accumulator + current
}

print("Sum of array:", sum)
// Output: Sum of array: 15

Key Points

• The reduce method takes an initial value and a closure that combines the accumulator with each element.
• Starting the accumulator at 0 is essential when summing integers to avoid incorrect results.
• The closure can be written using shorthand syntax: numbers.reduce(0, +) for brevity.
• reduce is a powerful tool for aggregating array values beyond just summing numbers.