Exception Handling in Dart

Exception handling is the process of responding to exceptional conditions or errors that occur during the execution of a program. These exceptional conditions can include runtime errors, such as null pointer exceptions, division by zero, or network failures. Exception handling allows developers to gracefully handle these errors, prevent application crashes, and provide meaningful feedback to users.

In the below PDF we discuss about Exception Handling in detail in simple language, Hope this will help in better understanding.

Dart Programming

Dart Exception Handling :

1. The try-catch Block:
In Dart, exceptions are handled using the try, catch, and finally blocks. The try block contains the code that may potentially throw an exception. If an exception occurs within the try block, control is transferred to the catch block, where the exception is caught and handled.

2. The finally Block:
Dart provides a finally block that can be used to execute code regardless of whether an exception is thrown. This block is commonly used for resource cleanup operations such as closing files or network connections.

Dart provides a structured approach to exception handling through the use of try, catch, and finally blocks:


try {
// Code that may throw an exception
} catch (exception) {
// Handle the exception
print('Exception caught: $exception');
} finally {
// Optional block, always executed regardless of whether an exception occurred
print('Finally block executed');

In this syntax:

  • The try block encloses the code that may potentially throw an exception.
  • The catch block is used to handle the exception if one occurs. It specifies the type of exception to catch, or it can catch any type of exception if no type is specified.
  • The finally block, which is optional, is always executed, regardless of whether an exception is thrown. It’s typically used for cleanup tasks such as closing files or releasing resources.

Example of Exception Handling in Dart:

Let’s consider a simple example where we attempt to parse a string into an integer:

void main() {
String input = '123abc';
try {
int number = int.parse(input);
print('Parsed number: $number');
} catch (e) {
print('Error: $e');
} finally {
print('Parsing complete.');

In this example, if the string input cannot be parsed into an integer, an exception will be thrown by int.parse(). The catch block will handle the exception by printing an error message, and the finally block will always execute, indicating that the parsing process is complete.


In conclusion, Exception handling is an essential aspect of writing reliable Dart code. By using try, catch, and finally blocks, developers can effectively manage errors and ensure the stability of their applications. Whether it’s handling unexpected runtime errors or signaling exceptional conditions within your code, Dart’s exception handling mechanism provides the tools you need to write robust and reliable software.

Related Question

Exception handling in Dart is the process of managing and responding to errors or exceptional situations that occur during the execution of a program.

In Dart, exceptions are represented by instances of classes that extend the Exception class or the Error class.

Try-catch blocks in Dart are used to handle exceptions. The code within the try block is monitored for exceptions, and if an exception occurs, the corresponding catch block is executed to handle the exception.

Yes, in Dart, you can have multiple catch blocks to handle different types of exceptions within a single try block.

The finally block in Dart is used to execute code regardless of whether an exception is thrown or not. It ensures that certain cleanup tasks are performed, such as closing files or releasing resources, irrespective of whether an exception occurred.


OOPS in Dart Object-Oriented Programming

Queue in Dart Programming A

Maps in Dart A Map

Set in Dart A Set

Dart Lists A Dart list

Strings in Dart A Dart

Functions in Dart In Dart,

Leave a Comment

Your email address will not be published. Required fields are marked *

// Sticky ads