Question

What is a decision structure?

Short answer

Answer: A decision structure, also known as a conditional structure or "if" statement, is a control structure that allows a program to execute different code based on a given condition. It usually consists of a condition that evaluates to either true or false, and separate code segments to be executed based on the outcome. Example in Python: ```python age = 16 if age >= 18: print("You are old enough to vote.") else: print("You are not old enough to vote.") ``` In this example, the program checks if the `age` variable is greater than or equal to 18. If true, it prints "You are old enough to vote," and if false, it prints "You are not old enough to vote."

Step-by-step solution

Definition of Decision Structure

A decision structure, sometimes referred to as a conditional structure or an "if" statement, is a control structure that allows a program to execute different code depending on a given condition. In simple terms, it's a way for the program to make decisions based on input or variable values. A decision structure typically consists of a condition that evaluates to either true or false and separate code segments to be executed based on the outcome.

Example of a Decision Structure

Take a look at the following example in the Python programming language. ```python age = 16 if age >= 18: print("You are old enough to vote.") else: print("You are not old enough to vote.") ``` Here, we have a variable `age`, and we want to check whether it is greater than or equal to 18. If the condition is met, i.e., `age >= 18` is true, the program will execute the `print("You are old enough to vote.")` statement. Otherwise, if the condition is false, the program will execute the `print("You are not old enough to vote.")` statement.

When and How to Use Decision Structures

Decision structures are used whenever a program needs to make a choice based on certain conditions. They help in controlling the flow of the program by executing a specific set of code when a particular condition is met. They are commonly used for input validation, branching between various cases in a problem, or determining which set of operations to perform based on specific conditions.