Where clauses for complex constraints in Swift - Mini Project: Build & Apply

Where clauses for complex constraints

📖 Scenario: You are building a small app that manages a list of people with their ages and cities. You want to filter this list to find people who meet certain complex conditions.

🎯 Goal: Learn how to use where clauses in Swift loops to apply complex filtering conditions easily and clearly.

📋 What You'll Learn

Create an array of tuples representing people with name, age, and city

Create a variable for the minimum age to filter

Use a for loop with a where clause to find people who are at least the minimum age and living in a specific city

Print the names of the people who meet these conditions

💡 Why This Matters

🌍 Real World

Filtering lists of people or items based on multiple conditions is common in apps like contact managers, event planners, or shopping apps.

💼 Career

Understanding how to use <code>where</code> clauses helps write clean, readable code for filtering data efficiently in Swift development jobs.

1

Create the people data

Create an array called people with these exact tuples: ("Alice", 30, "New York"), ("Bob", 25, "Los Angeles"), ("Charlie", 35, "New York"), ("Diana", 22, "Chicago"), ("Eve", 28, "New York").

Swift

# Create the array called people with the given tuples
# Your code here

Need a hint?

Use square brackets to create an array of tuples. Each tuple has a name (String), age (Int), and city (String).

2

Set the minimum age filter

Create a constant called minAge and set it to 28.

Swift

let people = [("Alice", 30, "New York"), ("Bob", 25, "Los Angeles"), ("Charlie", 35, "New York"), ("Diana", 22, "Chicago"), ("Eve", 28, "New York")]
# Create a constant minAge and set it to 28
# Your code here

Need a hint?

Use let to create a constant for the minimum age.

3

Filter people with a where clause

Write a for loop using for (name, age, city) in people where age >= minAge && city == "New York" to loop only over people who are at least minAge years old and live in "New York". Inside the loop, append the name to a new array called filteredNames. Create filteredNames as an empty array of strings before the loop.

Swift

let people = [("Alice", 30, "New York"), ("Bob", 25, "Los Angeles"), ("Charlie", 35, "New York"), ("Diana", 22, "Chicago"), ("Eve", 28, "New York")]
let minAge = 28
var filteredNames: [String] = []
# Use a for loop with a where clause to add names of people with age >= minAge and city == "New York" to filteredNames
# Your code here

Need a hint?

Use the where keyword after the for loop variables to filter the tuples. Append matching names to filteredNames.

4

Print the filtered names

Write a print statement to display the filteredNames array.

Swift

let people = [("Alice", 30, "New York"), ("Bob", 25, "Los Angeles"), ("Charlie", 35, "New York"), ("Diana", 22, "Chicago"), ("Eve", 28, "New York")]
let minAge = 28
var filteredNames: [String] = []
for (name, age, city) in people where age >= minAge && city == "New York" {
    filteredNames.append(name)
}
# Print the filteredNames array
# Your code here

Need a hint?

Use print(filteredNames) to show the result.