Зміст курсу
Introduction to Dart
Introduction to Dart
Bool, Equality and Relational Operators in Dart
Bool
We already know that bool is a data type that can have two values: true or false. It is used to store logical values.
javascript
Here we have created a variable
of data type bool with value true.
javascript
Here we have created a variable of data type bool with value false.
Equality and Relational Operators
You will use these operators in conditional expressions to make decisions in the program. For example, you can check whether the user has entered the correct password using the equality operator, or determine if a person has access to a specific resource based on their age. In such cases, the result of the comparison becomes a bool value, which helps you make decisions in your program based on conditions.
In this сhapter, we will learn how to store a bool value that will be computed based on whether the condition is true or false.
Examples
main
void main() { bool info = 10 > 2; // `true` print(info); }
10 > 2 is a true statement, so we see the result as true.
main
void main(){ String day1 = 'Monday'; String day8 = 'Monday'; print(day1 == day8); // `true` }
The variables day1 and day8 store the same values, so we get true as a result of the comparison.
Data Type Checking
The following operators do not check the value of the variable. They check the data type of the value.
main
void main() { print(4.2 is int); // `false` }
We get false because 4.2 is of the double type.
1. Consider the expression (4 != 5) and determine whether they evaluate to true or false.
2. Consider the expression (6 <= 6 + 3) and determine whether they evaluate to true or false.
3. Consider the expression (4 == 2 + 2) and determine whether they evaluate to true or false.
4. Consider the expression (var test = 33 is String;) and determine whether they evaluate to true or false.
Дякуємо за ваш відгук!
