91Ó°ÊÓ

A decision structure, also known as a control structure or conditional statement, is a fundamental programming concept that allows the program to make decisions and execute specific code segments based on whether a given condition is true or false.

There are three common types of decision structures: 1. Simple (if statement): In this structure, the program checks if a condition is true only. If it's true, specific code will run, otherwise, the program will skip it and continue executing the next lines of code. 2. If-else statement: In this structure, the program checks if a condition is true and executes the corresponding code block. If the condition is false, it runs another block of code instead. 3. Multi-branch (if-elif-else statement): Used in cases with multiple conditions that need to be tested. The program checks each condition in order and runs the first block of code with a true condition. If no conditions are true, it may run a default block of code in the 'else' statement.

Simple if statement: ``` x = 5 if x > 0: print("x is positive") ``` If-else statement: ``` x = -5 if x > 0: print("x is positive") else: print("x is negative or zero") ``` Multi-branch (if-elif-else) statement: ``` x = 0 if x > 0: print("x is positive") elif x < 0: print("x is negative") else: print("x is zero") ```