#8 Procedural programming

1. What is the key difference between a procedure and a function?

• A. A function always returns an integer value, unlike a procedure, which returns a Boolean
• B. A procedure always returns a value but in functions this is optional
• C. A function always returns a value whereas a procedure never does
• D. Procedures have global scope whereas functions have local scope

2. Which of these rules is true?

• A. Functions require parameters but procedures do not
• B. It is not essential to provide parameters to all functions or all procedures, but certain functions and procedures will require them
• C. Procedures require parameters but functions do not
• D. Functions and procedures always require parameters

3. What is meant by the 'return type' of a function?

• A. Whether the function is indented or not
• B. Whether it is a function or a procedure
• C. The data type of the value that the function produces when it completes
• D. The data type of the parameter taken in by the function

4. Which of the following is not compulsory when coding a function?

• A. An identifier (a function name)
• B. A return type
• C. A return statement
• D. A parameter

5. Which of these is a true statement about the scope of a variable?

• A. If a variable is declared within a function, it typically has global scope unless otherwise stated
• B. If a variable is declared within a function, it typically has local scope unless otherwise stated
• C. If a variable is declared within a function, it can be accessed easily from other functions
• D. If a variable is declared outside of a function, the various functions of that program cannot typically access it directly

6. What is considered good practice when considering scope rules?

• A. Make widespread use of global variables to improve the accessibility of all variables
• B. Make some global variables and then make some local variables using the same variable names as you used for the global variables as this will aid understanding of your program
• C. Try to use approximately 50:50 global and local variables in your program
• D. Stick mainly to local variables and pass values around as parameters rather than using global variables in most cases

7. What is meant by 'pass by value'?

• A. When a variable is passed to a subprogram, any changes made in the subprogram will be reflected in the original variable as well
• B. The variable will be passed as a parameter without using the variable name
• C. A second copy of the variable's value will be passed into the subprogram and any changes will only affect that second copy and not the original variable itself
• D. When a data structure such as an array is passed to a subprogram, the subprogram will only use the first value

8. What happens to a variable that is 'passed by reference' to a subprogram?

• A. The original variable is affected by any changes to the received variable that get made within the subprogram
• B. A second copy of the variable's value will be passed into the subprogram and any changes will only affect that second copy and not the original variable itself
• C. A new copy of the variable will be returned as an outcome of the subprogram (function)
• D. It will get destroyed and a new fresh copy will be created in the computer's memory

9. Which of these pseudocode statements will point to the final character in a string (called str) that uses zero-based indexing of its characters?

• A. CharAt(str, LENGTH(str)-1)
• B. CharAt(str,0)
• C. CharAt(str, LENGTH(str)+1)
• D. CharAt(str, LENGTH(str))

10. Which of these is the empty string?

• A. null
• B. " "
• C. ""
• D. "null"