How to create a directory in Kotlin?

In this tutorial, you shall learn how to create a directory in Kotlin, using File.mkdir() function, with example programs.

Kotlin – Create a directory

To create a directory in Kotlin, we can use mkdir() function from the java.io.File class.

Steps to create a directory

1. Consider that we are given a path to a directory.
2. Create a File object with the given directory path
3. Call mkdir() on the File object.

val directory = File("path/to/directory")
directory.mkdir()

Examples (3)

1. Create a new directory

In the following program, we create a directory named mydata.

Main.kt

import java.io.File

fun main() {
    val directory = File("mydata")
    directory.mkdir()
    println("Directory created successfully.")
}

Output

Directory created successfully.

2. Directory already exists

From the above program, we have created a directory named mydata.

Now, let us try to create a directory with the same name mydata.

Main.kt

import java.io.File

fun main() {
    val directory = File("mydata")
    directory.mkdir()
    println("Directory created successfully.")
}

Output

Directory created successfully.

Even if the directory is already present, the output seems to be same in both the above cases.

3. Check if directory exists before creating

We can check if directory is already present using File.exists() method. We can use this as a condition to check if the directory already exists, and only create the directory if it does not exist.

The following is the modified program with an if-else statement to create a new directory only if the directory does not exist.

Main.kt

import java.io.File

fun main() {
    val directory = File("mydata")
    if (!directory.exists()) {
        directory.mkdir()
        println("Directory created successfully.")
    } else {
        println("Directory already exists.")
    }
}

Output

Directory already exists.

Conclusion

In this Kotlin Tutorial, we learned how to create a new directory using File.mkdir() function.