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.