Chapter 24

Explain the Purpose and Use of Programming Concepts

In this chapter, you discover the purpose and use of programming concepts such as identifiers (variables, constants), containers (arrays, vectors), functions, and objects (properties, attributes, methods). This chapter covers CompTIA IT Fundamentals+ objective 4.3.

• Integer: A whole number, such as 3.

• Floating point: A number with a decimal, such as 54.4.

• Character: A single character, such as ‘z’. Escape sequences, which are used to control printer or display behavior, are also considered characters, such as ‘ ’ (new line). A universal character (Unicode character set or UCS) such as ‘u02C0’ (caron character) is also considered a single character. Character variables are enclosed in single quotes.

• String: A group of characters, escape sequences, or universal characters, such as “Hello, World!” String constants use double quotes.

To use a particular set of functions, the programmer must call (request) the function library in the program. For example, to use a mathematical function in C, such as abs (absolute value of an integer) or fmax (larger of two floating-point values), the math.h header (cmath header in C++) must be included in the program. To use an input/output function such as fopen (opens file) or fread (reads from file), the stdio.h header (cstdio header in C++) must be included in a program. To learn more about C++ functions, see https://www.tutorialspoint.com/cplusplus/cpp_functions.htm. To learn more about C functions, see https://www.tutorialspoint.com/cprogramming/c_functions.htm.

A user-defined function is defined at the top of a program. This enables the function to be referred to repeatedly in a program and the compiler to compile the code before it is used. For example, a function called drawshape is defined from the lines of code needed to draw a shape. However, after it is defined, the programmer can simply refer to the function drawshape and the program will locate the function and repeat it.

A function library is a collection of procedures that can be used (called) by other programs. By using a function library, a programmer can reduce development time by not needing to develop new code to perform a particular task. Some function libraries are included in a language, but others can be licensed from third-party developers.

However, in C#, properties are used to enable read, write, or compute access to a private field. This protects the contents of the data while enabling safe access. The access methods are often referred to as getter/setter.

array

attribute

character

container

constants

floating point

function

identifier

integer

methods

object

properties

variables

vector

1. Properties

2. OOP

3. Methods

4. Getter/setter

2. An object’s characteristics are called _______. (Fill in the blank.)

1. methods

2. attributes

3. properties

4. functions

3. You are creating a container to hold employee information. For the current workforce, you need space for 500 records. However, the company is planning to expand its workforce by an unknown amount. What type of object should you create to hold employee information?

1. Vector

2. Method

3. Array

4. Object

4. You are writing a program in C that will use mathematical functions. You need to include which of the following headers in your program?

1. abs

2. cmath

3. math.h

4. cstio

5. You are writing a program that needs a complex function. Instead of writing the function yourself, you can use a ___________. (Fill in the blank.)

1. user-defined function

2. function library

3. object

4. property

6. An attribute is a _________ of an object. (Fill in the blank.)

1. property

2. characteristic

3. method

4. function

7. After a conference, you are given a list of attributes for an employee. One of the potential attributes is actually a method. Which of the following is it?

1. Last name

2. Sign in

3. Shift

4. Employee number

8. You need to add a user-defined function to your program. Where should it be located?

1. Anywhere in the program code

2. End of the program

3. Immediately before its first use

4. Top of the program

9. At the beginning of your program, you enter several lines of code to create a function you call makeshape. To use the same procedure elsewhere in your program, which of the following should you do?

1. Reenter the code.

2. Refer to makeshape.

3. Add a line number for makeshape and use a GOTO statement.

4. Create a function library file for makeshape.

10. Which of the following is not a constant?

1. The number 3

2. A string of characters such as “Good morning”

3. Current date

4. The number 23.1

11. You are creating a program that calculates the number of days between the current date and the user’s birthday. Which of the following do you need to set up to get the user’s birthday?

1. Variable

2. Constant

3. Function

4. Container

12. An object is a combination of all of the following except:

1. Containers

2. Properties

3. Attributes

4. Procedures

13. Identifiers include which of the following?

1. Arrays and vectors

2. Properties and attributes

3. Variables and constants

4. Functions and methods

14. In JavaScript, in the variable (var) person, the firstname, lastname, age, and eyecolor can be defined as _________. (Fill in the blank.)

1. functions

2. constants

3. vectors

4. properties

15. A function is a(n) _________or _________inside a larger program. (Fill in the blanks.)

1. identifier or container

2. escape sequence or universal character

3. subroutine or procedure

4. conjunction or junction