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Comparison operators

Learn to compare values with ==, !=, <, >, <= and >=.

Comparison operators

Comparison operators compare two values and return a bool (true/false). Six basic operators: ==, !=, <, >, <=, >=.

Important: = is assignment, == is equality comparison. x = 5 assigns 5 to x; x == 5 asks whether x equals 5.

Since the result is a bool, it is used in if conditions: if (age >= 18) { print('Adult'); }.

Practice Print comparisons

Write print(5 == 5), print(3 != 7) and print(4 < 10) inside void main().

Starter code

main.dart
// Comparison operations

Sample solution

main.dart
void main() {
  print(5 == 5);
  print(3 != 7);
  print(4 < 10);
}

Expected output

true
true
true

Practice Compare with condition

Declare var score = 75;. Check with if (score >= 50) and print print('Passed').

Starter code

main.dart
// Compare with a condition

Sample solution

main.dart
void main() {
  var score = 75;
  if (score >= 50) {
    print('Passed');
  }
}

Expected output

Passed

Questions and answers

Review the lesson questions together with their answers. To test yourself, solve the lesson interactively.

1 What is the difference between = and ==?

  • = assigns, == compares Correct answer
  • They are the same
  • == is faster
  • = only in classes

Explanation: = assigns; == checks equality.

2 Comparison operators

Term Meaning
== Equal
!= Not equal
< Less than
> Greater than

3 Not equal

Question 
if (a ____ 5) { print('different'); }
Answer 
if (a != 5) { print('different'); }

Explanation: If a is not 5, it returns true.

All lessons in Beginner

1 Dart basics

  1. What is Dart?
  2. Your first program
  3. dart run
  4. Comments
  5. String interpolation
  6. Summary - Dart basics

2 Variables

  1. var and type
  2. final
  3. const
  4. late
  5. Null safety
  6. Summary - Variables

3 Data types

  1. Integer types
  2. Floating-point types
  3. bool and String
  4. Type inference
  5. dynamic
  6. Summary - Data types

4 Project: Calculator

  1. Project design
  2. Add and subtract
  3. Multiply and divide
  4. Error handling
  5. Putting it together

5 Operators

  1. Arithmetic operators
  2. Assignment operators
  3. Comparison operators
  4. Logical operators
  5. Null-aware operators
  6. Summary - Operators

6 Strings

  1. Creating strings
  2. String interpolation
  3. length and methods
  4. substring
  5. contains and indexOf
  6. Summary - Strings

7 Conditionals

  1. The if statement
  2. else and else if
  3. switch
  4. Pattern matching
  5. Ternary
  6. Summary - Conditionals

8 Loops

  1. The for loop
  2. The while loop
  3. The do-while loop
  4. for-in
  5. break and continue
  6. Summary - Loops

9 Project: Shopping cart

  1. Cart design
  2. Adding items
  3. Calculating totals
  4. Listing the cart
  5. Putting it together

10 Lists

  1. Creating lists
  2. List access
  3. add and remove
  4. length and contains
  5. List methods
  6. Summary - Lists

11 Sets and Maps

  1. Set
  2. Set operations
  3. Map
  4. Map operations
  5. Map iteration
  6. Summary - Sets and Maps

12 Functions

  1. Defining functions
  2. Return values
  3. Arrow functions
  4. Optional parameters
  5. First-class functions
  6. Summary - Functions

13 Null safety in depth

  1. Nullable types
  2. Null-aware operators
  3. The ! operator
  4. late
  5. Null check
  6. Summary - Null safety

14 Class basics

  1. class
  2. Constructor
  3. Instance variables
  4. Methods
  5. this
  6. Summary - Class basics

15 Project: To-do CLI

  1. Task model
  2. Adding tasks
  3. Listing tasks
  4. Completing tasks
  5. Putting it together

16 Advanced string operations

  1. split and join
  2. replace
  3. trim and pad
  4. RegExp
  5. StringBuffer
  6. Summary - Advanced strings

17 Enums

  1. Defining enums
  2. Enum values
  3. Enhanced enums
  4. switch with enum
  5. Enum and patterns
  6. Summary - Enums

18 Exceptions

  1. try/catch
  2. throw
  3. finally
  4. The Exception class
  5. on clause
  6. Summary - Exceptions

19 Async basics

  1. Future
  2. async/await
  3. then
  4. Future.error
  5. Future.wait
  6. Summary - Async basics

20 Beginner final

  1. Project design
  2. Classes
  3. Collections
  4. Error handling
  5. Putting it together