Creating strings

Learn to create strings and use the length property.

Creating strings

A String holds text and is written in double quotes. For example val s = "Hello" creates a String. In Kotlin, Strings are immutable: once created, their content does not change.

val s = "Kotlin"
println(s.length)  // 6

The length of a String is given by the length property. Unlike Java, there are no parentheses; length is a property, not a method. The first character has index 0, the last has index length - 1. Going beyond throws IndexOutOfBoundsException.

length is a property

In Kotlin, length is a property, not a method. So no parentheses are used: s.length is correct, s.length() is wrong.

val s = "Hello"
val n = s.length   // 5
// s.length()  // compile error

In Java, length() is a method and needs parentheses. When moving to Kotlin this is a common mix-up; the compiler warns you at build time.

For the empty String "", length returns 0.

Exercise Create a string and print its length

Write a fun main(). Assign "Alex" to val name. Print the string with println(name) and its length with println(name.length) on separate lines.

Show example solution

fun main() {
    val name = "Alex"
    println(name)
    println(name.length)
}

Test yourself

What does "Kotlin".length return?
- 5
- 6
- 7
- 0
Show answer

6 — "Kotlin" has 6 characters, length returns 6.
Complete the length call
```
val n = name.____
```
Show answer
```
val n = name.length
```
Match the string concepts

length

Length
"Hello"

String example
0

First index
length - 1

Last index

Next lesson: String templates

We Are Enhancing Your Experience

Cookie Preferences

Strictly Necessary Cookies

Analytical Cookies