Multiline strings with trimIndent in Kotlin - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of trimIndent on a multiline string

What is the output of this Kotlin code snippet?

Kotlin

val text = """
    Hello,
      Kotlin!
      Welcome to trimIndent.
    """.trimIndent()
println(text)

A Hello,\nKotlin!\nWelcome to trimIndent.

B |Hello,\n | Kotlin!\n | Welcome to trimIndent.

C Hello,\n Kotlin!\n Welcome to trimIndent.

D Hello,\n Kotlin!\n Welcome to trimIndent.

💡 Hint

trimIndent removes the common minimal indent from all lines.

The trimIndent function removes the smallest common indent from every line. The first line has a 4-space indent, while the second and third lines have 6-space indents. It removes 4 spaces from each, keeping the relative indentation.

❓ Predict Output

intermediate

Effect of trimIndent on uneven indentation

What will be printed by this Kotlin code?

Kotlin

val poem = """
        Roses are red,
          Violets are blue,
        Kotlin is fun,
          And so are you.
    """.trimIndent()
println(poem)

A Roses are red,\nViolets are blue,\nKotlin is fun,\nAnd so are you.

B Roses are red,\n Violets are blue,\nRoses are red,\n And so are you.

C Roses are red,\n Violets are blue,\nKotlin is fun,\n And so are you.

D Roses are red,\n Violets are blue,\n Kotlin is fun,\n And so are you.

💡 Hint

trimIndent removes the smallest indent common to all lines.

The smallest indent common to all lines is 8 spaces. After removing it, lines with more indentation keep their extra spaces.

🔧 Debug

advanced

Why does this trimIndent code produce unexpected output?

Consider this Kotlin code: val message = """ Hello, World! """.trimIndent() println(message) Why does the output keep the extra spaces before 'World!'?

A Because trimIndent only removes the smallest common indent from all lines, and 'World!' line has more indentation.

B Because trimIndent removes all indentation from every line unconditionally.

C Because trimIndent only removes indentation if lines start with a margin prefix like '|'.

D Because trimIndent removes trailing spaces but not leading spaces.

💡 Hint

Think about how trimIndent calculates the indent to remove.

trimIndent finds the smallest indent common to all lines and removes that. Lines with more indentation keep their extra spaces.

📝 Syntax

advanced

Identify the syntax error in this multiline string usage

Which option contains a syntax error when using trimIndent with multiline strings in Kotlin?

Kotlin

val text = """
    Line one
    Line two
    Line three
""".trimIndent()

A

val text = """
    Line one
    Line two
    Line three
"".trimIndent()

B

)(tnednImirt."""
eerht eniL    
owt eniL    
eno eniL    
""" = txet lav

C

val text = """
    Line one
    Line two
    Line three
""".trimIndent()

D

al text = """
    Line one
    Line two
    Line three
""".trimIndent()

💡 Hint

Check the closing triple quotes and method call syntax.

Option A has only two double quotes to close the string, causing a syntax error. Triple quotes must be closed with exactly three double quotes.

🚀 Application

expert

How many lines does this trimmed multiline string contain?

Given this Kotlin code, how many lines does the resulting string contain after trimIndent is applied?

Kotlin

val data = """
        {
            "name": "Alice",
            "age": 30
        }
    """.trimIndent()

val linesCount = data.lines().size
println(linesCount)

A 6

B 5

C 4

D 7

💡 Hint

Count the lines inside the triple quotes after trimming indentation.

The string has 5 lines: '{', ' "name": "Alice",', ' "age": 30', '}', and an empty line is not present. trimIndent does not remove lines, only indentation.