**Course Title:** MATLAB Programming: Applications in Engineering, Data Science, and Simulation **Section Title:** MATLAB Control Structures **Topic:** Conditional statements: if-else, switch-case **Learning Objectives:** 1. Understand the concept of conditional statements in MATLAB programming. 2. Learn how to use if-else statements to control program flow based on conditions. 3. Understand how to use switch-case statements for multiple condition testing. 4. Apply conditional statements to real-world problems in engineering, data science, and simulation. **What are Conditional Statements?** Conditional statements are programming constructs that allow you to control the flow of a program based on certain conditions. In MATLAB, you can use if-else statements and switch-case statements to execute different blocks of code based on conditions. ### If-Else Statements If-else statements are the most common type of conditional statement in MATLAB. The basic syntax is: ```matlab if condition % code to execute if condition is true else % code to execute if condition is false end ``` Here's an example of how to use an if-else statement to check if a number is greater than 10: ```matlab x = 15; if x > 10 disp('x is greater than 10'); else disp('x is less than or equal to 10'); end ``` In this example, since `x` is 15, which is greater than 10, the program will display "x is greater than 10". You can also use multiple conditions with `if-elseif-else` statements: ```matlab x = 15; if x > 20 disp('x is greater than 20'); elseif x > 10 disp('x is greater than 10 but less than or equal to 20'); else disp('x is less than or equal to 10'); end ``` In this example, since `x` is 15, which is greater than 10 but less than or equal to 20, the program will display "x is greater than 10 but less than or equal to 20". **Multiple Conditions with `if` Statements** You can also use multiple conditions with `if` statements using logical operators. For example: ```matlab x = 15; y = 20; if x > 10 && y > 10 disp('both x and y are greater than 10'); end ``` In this example, since both `x` and `y` are greater than 10, the program will display "both x and y are greater than 10". ### Switch-Case Statements Switch-case statements are used when you want to test multiple conditions and execute different blocks of code based on those conditions. The basic syntax is: ```matlab switch value case value1 % code to execute if value matches value1 case value2 % code to execute if value matches value2 case value3 % code to execute if value matches value3 otherwise % code to execute if value does not match any of the above end ``` Here's an example of how to use a switch-case statement to check the value of a variable: ```matlab x = 2; switch x case 1 disp('x is equal to 1'); case 2 disp('x is equal to 2'); case 3 disp('x is equal to 3'); otherwise disp('x is not equal to 1, 2 or 3'); end ``` In this example, since `x` is 2, the program will display "x is equal to 2". **Example Use Case** Suppose you are developing a program to classify numbers as positive, negative, or zero. You can use an if-else statement to achieve this: ```matlab x = -10; if x < 0 disp('x is negative'); elseif x > 0 disp('x is positive'); else disp('x is zero'); end ``` In this example, since `x` is -10, which is negative, the program will display "x is negative". ### Key Concepts and Practical Takeaways * Conditional statements are used to control the flow of a program based on conditions. * If-else statements are the most common type of conditional statement in MATLAB. * Switch-case statements are used to test multiple conditions and execute different blocks of code. * Use logical operators to combine multiple conditions with `if` statements. * Practice using if-else and switch-case statements to solve real-world problems in engineering, data science, and simulation. **Additional Resources** * MATLAB Documentation: [Conditional Statements](https://www.mathworks.com/help/matlab/flow-control.html) * MATLAB Documentation: [if Statements](https://www.mathworks.com/help/matlab/ref/if.html) * MATLAB Documentation: [switch Statements](https://www.mathworks.com/help/matlab/ref/switch.html) **Next Topic:** Looping structures: for, while, and nested loops. **Do you have any questions or need further clarification on conditional statements in MATLAB? Please leave a comment below.**