Why error handling matters in Kotlin

Introduction

Error handling helps your program deal with problems without crashing. It keeps your app working smoothly and lets you fix issues nicely.

When reading a file that might not exist

When asking for user input that could be wrong

When connecting to the internet which might fail

When dividing numbers and the divisor could be zero

When working with data that might be missing or wrong

Syntax

Kotlin

try {
    // code that might cause an error
} catch (e: Exception) {
    // code to handle the error
} finally {
    // code that runs no matter what
}

try block holds code that might cause an error.

catch block handles the error if it happens.

Examples

This tries to convert text to a number. If it fails, it prints a message.

Kotlin

try {
    val number = "abc".toInt()
} catch (e: NumberFormatException) {
    println("That is not a number!")
}

This catches the error when dividing by zero and shows a warning.

Kotlin

try {
    val result = 10 / 0
} catch (e: ArithmeticException) {
    println("Cannot divide by zero!")
}

Sample Program

This program tries to change text to a number. If it fails, it tells the user. It always prints a final message.

Kotlin

fun main() {
    val input = "hello"
    try {
        val number = input.toInt()
        println("Number is $number")
    } catch (e: NumberFormatException) {
        println("Oops! '$input' is not a number.")
    } finally {
        println("End of program.")
    }
}

Important Notes

Always handle errors to avoid program crashes.

Use finally to run code no matter what, like closing files.

Summary

Error handling keeps programs safe and user-friendly.

Use try and catch to manage problems.

Good error handling helps fix issues and keeps apps running.