Boolean Expression

Definition

A Boolean expression is a logical statement that evaluates to either true or false. It is a fundamental concept in programming that is used to control the flow of execution in a program based on conditions.

5 Must Know Facts For Your Next Test

1. Boolean expressions are the foundation of conditional logic in programming, allowing for decision-making based on the evaluation of conditions.
2. The result of a Boolean expression is either true or false, which can be used to control the flow of execution in a program.
3. Boolean expressions can be constructed using a variety of comparison operators, such as <, >, ==, !=, >=, and <=.
4. Logical operators, such as AND, OR, and NOT, can be used to combine multiple Boolean expressions to create more complex conditions.
5. Boolean expressions are commonly used in control flow statements like if-else statements, conditional expressions, and while loops to determine which code block should be executed.

Review Questions

• Explain how Boolean expressions are used in if-else statements to control the flow of execution in a program.
  • In if-else statements, Boolean expressions are used to evaluate a condition. If the Boolean expression evaluates to true, the code block associated with the if statement is executed. If the Boolean expression evaluates to false, the code block associated with the else statement (if present) is executed instead. This allows the program to make decisions and follow different execution paths based on the outcome of the Boolean expression.
• Describe the role of Boolean expressions in conditional expressions (also known as ternary operators) and how they differ from if-else statements.
  • Conditional expressions, or ternary operators, use a Boolean expression to determine which of two values should be assigned to a variable. The syntax is: condition ? valueIfTrue : valueIfFalse. If the Boolean expression evaluates to true, the value on the left side of the colon is assigned; otherwise, the value on the right side is assigned. Conditional expressions provide a more concise way to express simple if-else logic compared to traditional if-else statements.
• Analyze the role of Boolean expressions in while loops and how they control the loop's execution.
  • In while loops, a Boolean expression is used as the loop condition. The loop will continue to execute as long as the Boolean expression evaluates to true. Once the expression becomes false, the loop terminates. This allows for repeated execution of a block of code based on a specific condition. The Boolean expression in a while loop is crucial for controlling the loop's behavior and ensuring it runs for the desired number of iterations or until a certain condition is met.

Related terms

Logical Operators: Operators used to combine or negate Boolean expressions, such as AND, OR, and NOT.

Comparison Operators: Operators used to compare values and create Boolean expressions, such as <, >, ==, and !=.

Conditional Statements: Programming constructs that execute different code paths based on the evaluation of a Boolean expression.