Kotlin String endsWith

The endsWith function in Kotlin is used to check if a string ends with a specified suffix. This function belongs to the String class in the Kotlin standard library and provides a straightforward way to perform suffix matching within a string.

Table of Contents

1. Introduction
2. endsWith Function Syntax
3. Understanding endsWith
4. Examples
   • Basic Usage
   • Using endsWith with Ignore Case
   • Checking for Multiple Suffixes
5. Real-World Use Case
6. Conclusion

Introduction

The endsWith function checks if a string ends with a specified suffix. This is useful for various string operations such as validation, formatting, and file type checking.

endsWith Function Syntax

The syntax for the endsWith function is as follows:

fun String.endsWith(suffix: String, ignoreCase: Boolean = false): Boolean
fun String.endsWith(suffix: Char, ignoreCase: Boolean = false): Boolean

Parameters:

• suffix: The suffix to check for at the end of the string.
• ignoreCase: If true, the search will ignore case differences (default is false).

Returns:

• true if the string ends with the specified suffix, false otherwise.

Understanding endsWith

The endsWith function checks if the string ends with the given suffix. It can perform a case-sensitive or case-insensitive check based on the ignoreCase parameter.

Examples

Basic Usage

To demonstrate the basic usage of endsWith, we will create a string and check if it ends with a specific suffix.

Example

fun main() {
    val text = "Hello, World!"
    val endsWithExclamation = text.endsWith("!")
    val endsWithWorld = text.endsWith("World!")

    println("Does the text end with '!'? $endsWithExclamation")
    println("Does the text end with 'World!'? $endsWithWorld")
}

Output:

Does the text end with '!'? true
Does the text end with 'World!'? true

Using endsWith with Ignore Case

This example shows how to use the ignoreCase parameter for case-insensitive suffix checking.

Example

fun main() {
    val text = "Hello, World!"
    val endsWithWorldIgnoreCase = text.endsWith("world!", ignoreCase = true)

    println("Does the text end with 'world!' (ignore case)? $endsWithWorldIgnoreCase")
}

Output:

Does the text end with 'world!' (ignore case)? true

Checking for Multiple Suffixes

This example demonstrates how to check for multiple possible suffixes using a combination of endsWith and other functions.

Example

fun main() {
    val fileName = "document.txt"
    val endsWithTxt = fileName.endsWith(".txt")
    val endsWithDoc = fileName.endsWith(".doc")

    println("Does the file name end with '.txt'? $endsWithTxt")
    println("Does the file name end with '.doc'? $endsWithDoc")
}

Output:

Does the file name end with '.txt'? true
Does the file name end with '.doc'? false

Real-World Use Case

Validating File Extensions

In real-world applications, the endsWith function can be used to validate file extensions, ensuring that files have the correct format.

Example

fun main() {
    val fileName = "report.pdf"

    if (fileName.endsWith(".pdf")) {
        println("The file is a PDF document.")
    } else if (fileName.endsWith(".docx")) {
        println("The file is a Word document.")
    } else {
        println("Unknown file format.")
    }
}

Output:

The file is a PDF document.

Conclusion

The endsWith function in Kotlin's String class is a convenient method for checking if a string ends with a specified suffix. It provides a simple way to perform suffix matching for various use cases, including validation, formatting, and file type checking. 

By understanding and using this function, you can effectively manage suffix-matching operations in your Kotlin applications.