The if-else statement is a fundamental construct in programming that allows you to execute different blocks of code based on specific conditions. In Flutter, if-else statements are used extensively to control the flow of your application’s logic and user interface.

Syntax of If-Else Statements in Dart (Flutter’s Programming Language):

The syntax of an if-else statement in Dart is as follows.

if (condition) {
  // Code to execute if the condition is true
} else {
  // Code to execute if the condition is false
}

In this syntax:

• condition is a boolean expression that evaluates to either true or false.
• The code block inside the if statement is executed if the condition is true.
• The code block inside the else statement is executed if the condition is false.

Example: Using If-Else Statements in Flutter Widgets:

Let’s consider a simple example where we want to display a message based on whether a user is logged in or not. We can achieve this using if-else statements in Flutter widgets.

import 'package:flutter/material.dart';

class HomePage extends StatelessWidget {
  final bool isLoggedIn = true;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Conditional Statements in Flutter'),
      ),
      body: Center(
        child: isLoggedIn
            ? Text('Welcome, User!')
            : Text('Please log in to continue.'),
      ),
    );
  }
}

void main() {
  runApp(MaterialApp(
    home: HomePage(),
  ));
}

We define a boolean variable isLoggedIn that determines whether the user is logged in.

Inside the build method of the HomePage widget, we use an if-else statement to conditionally display different messages based on the value of isLoggedIn.

If isLoggedIn is true, we display a welcome message. Otherwise, we prompt the user to log in.