Question

What statement do you use in Python to write a dual alternative decision structure?

Short answer

Answer: A dual alternative decision structure is a programming concept that allows the execution of one of two blocks of code based on a certain condition. In Python, it is implemented using the "if-else" statement, where the "if" keyword is followed by a condition and the first block of code, and the "else" keyword defines the second block of code to be executed when the condition is false.

Step-by-step solution

Understand Dual Alternative Decision Structure

A dual alternative decision structure is a decision structure in programming that allows the execution of one of two blocks of code based on a certain condition. If the condition turns out to be true, the first block of code is executed, and if it is false, the second block of code is executed. It is often used to handle situations where there are two possible outcomes based on the input data.

Identify the Statement

In Python, the dual alternative decision structure is implemented using the "if-else" statement. The "if" keyword is followed by a condition, and the block of code that should execute if the condition is true. Then, the "else" keyword is used to define the block of code that should execute if the condition is false.

Write a Basic Example

Let's say we want to write a Python program to determine if a number is even or odd. To use a dual alternative decision structure, we will first need a condition: the remainder of the number divided by 2 is equal to 0. Then, we will use an "if-else" statement to print the appropriate result. Here is the sample code for this example: ```python number = 5 if number % 2 == 0: print("The number is even.") else: print("The number is odd.") ```

Analyze the Example

In this example, we first define a variable called "number" and assign it a value of 5. Then, we use an "if" statement with the condition `(number % 2 == 0)`. If the remainder of the division of "number" by 2 is 0 (which means the number is even), the first block of code after the "if" statement will be executed and it will print "The number is even". If the condition is false (the number is not even, so it's odd), then the block of code after the "else" keyword will be executed, printing "The number is odd".