Recap - Sigma Function

Part of the Fundamentals section of Coddy's Swift journey — lesson 55 of 86.

Challenge

Easy

Create a function called sigma that calculates the sum of all integers from 1 to a given number.

Parameters:

n (Int): The upper limit of the sum (use _ to omit the argument label)

Returns: The sum of all integers from 1 to n (Int)

After defining the function, read an integer from input, call the sigma function with that value, and print the result.

You will receive the following input:

A single integer representing the value of n

For example, if the input is 5, the function calculates 1 + 2 + 3 + 4 + 5 = 15, so the output should be:

Try it yourself

// TODO: Define the sigma function that calculates the sum of integers from 1 to n
// Use _ to omit the argument label


// Read input
let n = Int(readLine()!)!

// Call the function and print the result
print(sigma(n))

All lessons in Fundamentals

1Introduction

The Language Hello World!Comments

4Operators Part 1

Arithmetic Operators Modulo Operator Compound Assignment Recap - Simple Math Comparison Operators

7Basic IO

Print Function String Interpolation ReadLine Input Type Conversion Recap - Till 120 Recap - True or False

10Functions

Declare A Function Parameters And Arguments Return Values Argument LabelsRecap - Sigma FunctionRecap - Validation Function Default Values

13Iterating Over Sequences

Iterating Over Elements The Enumerated Method Iterating Over Strings P1 Iterating Over Strings P2

16Final Challenges

Flat Asterisk Pyramid Pattern Finder What To Buy

2Variables

Let vs Var Type Annotations Numbers String Boolean Naming Conventions Recap - Initialize Variables

5Operators Part 2

Logical Operators Part 1 Logical Operators Part 2 Recap - Simple Logic Logical Operators Part 3 Ternary Operator

8Bill Split Calculator

Welcome Message Getting Input

Calculating Tip And Total

Splitting The Bill

Formatted Output

11FizzBuzz with a Twist

Game Overview The FizzBuzz Function

Looping The Numbers

Adding The Twist

14Arrays Advanced

Array Slicing Part 1 Array Slicing Part 2 Sequence Operators The Contains Method