String methods (substring, split, trim) in Kotlin - Mini Project: Build & Apply

Working with String Methods in Kotlin

📖 Scenario: You are helping a small bookstore organize customer feedback. The feedback comes as a long string with customer names and their comments separated by commas. You want to clean and split this data to make it easier to read and analyze.

🎯 Goal: Build a Kotlin program that trims extra spaces from the feedback string, splits it into individual feedback entries, and extracts the customer names using substring.

📋 What You'll Learn

Create a string variable with the exact feedback text

Create a variable to hold the trimmed version of the feedback string

Split the trimmed string into a list of feedback entries

Extract customer names from each feedback entry using substring

Print the list of customer names

💡 Why This Matters

🌍 Real World

Cleaning and organizing customer feedback or any text data is common in businesses to understand opinions and improve services.

💼 Career

Knowing how to manipulate strings is essential for software developers, data analysts, and anyone working with text processing or user input.

1

Create the feedback string

Create a string variable called feedback with this exact value: " Alice: Loved the new books, Bob: Great service, Charlie: Will visit again "

Kotlin

# Create the feedback string variable called feedback
# Your code here

Need a hint?

Use val feedback = "your string here" to create the string.

2

Trim the feedback string

Create a variable called trimmedFeedback that holds the result of trimming spaces from feedback using the trim() method

Kotlin

val feedback = "  Alice: Loved the new books, Bob: Great service, Charlie: Will visit again  "
# Trim the feedback string and store in trimmedFeedback
# Your code here

Need a hint?

Use val trimmedFeedback = feedback.trim() to remove spaces at the start and end.

3

Split the trimmed feedback into entries

Create a variable called entries that splits trimmedFeedback by comma and space ", " using the split() method

Kotlin

val feedback = "  Alice: Loved the new books, Bob: Great service, Charlie: Will visit again  "
val trimmedFeedback = feedback.trim()
# Split trimmedFeedback into entries by ", "
# Your code here

Need a hint?

Use val entries = trimmedFeedback.split(", ") to split the string into parts.

4

Extract and print customer names

Create a list called names by extracting the substring before the colon ':' from each entry in entries. Then print names. Use a for loop with variable entry and the substringBefore method.

Kotlin

val feedback = "  Alice: Loved the new books, Bob: Great service, Charlie: Will visit again  "
val trimmedFeedback = feedback.trim()
val entries = trimmedFeedback.split(", ")
# Extract names from entries and print the list
# Your code here

Need a hint?

Use entry.substringBefore(':') inside a loop to get each name, then print the list.