How to rename a file in Kotlin?

In this tutorial, you shall learn how to rename a file in Kotlin identified by a given path, using File.renameTo() function, with example programs.

Kotlin – Rename a File

To rename a file in Kotlin, you can use renameTo() function of java.io.File class.

Steps to rename a file

1. Consider that we have a file (source) given by a path, and have to rename this file to a new name (target).
2. Create two file objects: one for the source file, and one for the target file, with respective paths.
3. Call renameTo() function on the source file and pass the target file as argument. The function returns true if renaming is successful, else it returns false.

val sourceFile = File("path/to/source")
val targetFile = File("path/to/target")
sourceFile.renameTo(targetFile)

Example

Consider that we have a file named info.txt, and we would like to rename it to info_1.txt.

In the following program, we shall rename the file info.txt to info_1.txt by using File.renameTo() function.

Main.kt

import java.io.File

fun main() {
    val sourceFile = File("info.txt")
    val targetFile = File("info_1.txt")
    if ( sourceFile.renameTo(targetFile) ) {
        println("File renamed successfully.")
    } else {
        println("Could not rename file.")
    }
}

Output

File renamed successfully.

Reference tutorials for the above program

• Kotlin – If-Else

Conclusion

In this Kotlin Tutorial, we learned how to rename a file using java.io.File.renameTo() function.