Software development set #1 (IT fundamentals)

In the context of object-oriented programming, what is a property of an object?

• property is an contract between an object and its subclasses

• a property is a specific action or function the object can perform

• a property is a relationship between two or more objects

• a property is a characteristic or attribute of an object used to hold data

Answer explanation

In object-oriented programming, properties (also known as attributes) are used to hold information or data for an object. They represent the object's state. Actions or functions that an object can perform are referred to as methods, not properties. The relationship between two or more objects isn't considered a property. This concept is more related to ideas like association, aggregation, and inheritance. A contract between an object and its subclasses is more related to concepts like interfaces or abstract classes, not properties.

Assembly language is a type of programming language used in various computing contexts. Which of the following options BEST describes the characteristics of assembly language?

• its a query language used mainly for managing and manipulating databases

• its a low level language closely related to machine code bur readable by humans

• its a high level language used primarily for web development

• its an interpreted language with functionalities like scripting languages such as python to javascript

Answer explanation

ssembly language is a low-level programming language. It is alphanumeric, making it more readable by humans than raw machine code but still related closely enough to the machine code to offer direct control over the computer's hardware. High-level languages, like JavaScript, Python, or Ruby, provide a higher level of abstraction from the computer hardware and are usually easier to write and read. Assembly language, on the other hand, is lower-level and provides less abstraction, making it more difficult to write and read but providing a close relation to the hardware. Assembly language is not interpreted. It's compiled or assembled directly into machine code. Moreover, assembly language doesn't typically have high-level functionalities like Python or JavaScript. It involves working directly with the system's hardware. Query languages, like SQL, are used for manipulating and managing data in databases whereas assembly language is a low-level language used for direct interaction with a computer's hardware. They serve fundamentally different purposes in computing.

Why would a programmer opt to use a query language?

• to design and to manipulate database effectively.

• to develop mobile applications for various platforms

• to write impressive graphical user interface

• to write high-performance , system level programs.

Answer explanation

Query languages like SQL are designed to allow users to access, manipulate, and express database queries. Mobile application development requires general-purpose languages capable of handling various aspects of software development, not domain-specific languages like query languages. System-level programming typically requires lower-level, compiled languages, whereas query languages are high-level, interpreted, and domain-specific. Query languages are not specifically designed for creating graphical user interfaces.

You are given an array arr = [12, 7, 15, 21, 27] in a programming language. You wish to access the third element of this array using zero-based indexing. Which of the following sorts of access will provide you the desired result?

• arr[0]

• arr[2]

• arr[3]

• arr[1]

Answer explanation

Explanation

In zero-based indexing, the first element of the array is at index 0, second element is at index 1, and so forth. Therefore, the third element is at index 2. arr[0] accesses the first element of the array in zero-based indexing, not the third. arr[1] will access the second element of the array in zero-based indexing, not the third. arr[3] will access the fourth element of the array in zero-based indexing, not the third.

In software programming, what functions do loops typically serve? (Select TWO).

• establish data connectivity

• make secret function variables

• encrypt the code

• interactively access array elements

• perform a task repeatedly until a certain condition is met

Answer explanation

Performing a task repeatedly until a certain condition is met is the basic definition of a loop. For example, as long as the condition 'i < 10' is true, code within a 'for' loop will execute. Iteratively accessing array elements is one of the main uses of loops in programming. Loops can be used to access, modify, and display each element in an array one by one. Making function variables secret isn't related to looping. This is done through concepts of scope and access modifiers not through loops. Encrypting the code is not related to looping. Encryption is a separate process of converting data into a code to prevent unauthorized access. Establishing data connectivity isn't related to loops in programming. This is primarily concerned with networking and databases.

What is a significant difference between Assembly language and Machine code?

• Assembly language is not translated into machine code for execution

• machine code pertains to high-level languages , while assembly can be read and written

• assembly language is a platform-independent, while machine code is platform-dependent

• machine code cannot be read or written by programmers , while assembly language can be read and written.

Answer explanation

Assembly language provides a readable notation for machine code instructions, making it easier for people to read and write. Machine code consists of binary instructions directly understood by the CPU, which are not human-friendly. Assembly language is translated into machine code for execution. Sometimes it is done ahead of time (ahead of time compilation) or during runtime (JIT compilation). Both Machine code and Assembly language are considered low-level languages. Both Assembly language and Machine code are platform-dependent as they are directly linked to specific hardware architectures.

In a high-level programming language, you have a repeating sequence of actions that needs to process different sets of data at various points in your code. Which programming concept is BEST suited to bundle these actions for future reuse and maintain a DRY (Don't Repeat Yourself) approach?

• creating a function that encapsulates the repeating actions

• defining an array that hold pieces of the repeating code.

• establish a list of variables for each of the repeating action

• creating a loop structure to continuously perform he repeating action.

Answer explanation

Functions are designed for this kind of task, encapsulating actions and allowing for code reusability and a DRY approach. Arrays are used for holding data, not pieces of code or actions. Variables hold data, not actions. So this approach won't help to encapsulate the repeating actions. While loops can repeat code, they are less versatile for this task than functions, especially when the repeated actions need to be performed at various points in the code.

Susan is developing a program where the user must input a discount rate as a decimal number to calculate the final price of a product. However, Susan notices that whenever a user inputs a value like 0.15, the program is throwing an error. Which of the following is the MOST likely error?

• the program can only accept negative numbers

• the user input is being received as a string

• the program field was designed to accept an integer, not a float

• the program doesn't recognize decimal numbers

Answer explanation

If the programmer designed the program to accept integers only in the specific field for the discount rate, this will cause an error whenever a float number (like 0.15) is inputted. Integer fields will not successfully store float values because of the decimal point. Most programming languages are absolutely capable of recognizing and working with decimal numbers in the form of float values. They are an essential data type, and their use in calculations is very common. While it's true that user input is often initially received as a string type in many programming languages, good programming practice involves converting this input to the needed data type. In Susan's case, an error from having a string where a float or integer is expected should only occur if this conversion step is overlooked. However, it wouldn't specifically cause trouble with inputting float values, but rather any numeric input. There's no reason that a program should be specifically limited to only accept negative numbers unless it has been explicitly programmed to do so. In general, number fields in programs should be able to accept both positive and negative values unless specified otherwise.

In the context of object-oriented programming (OOP), how are functions typically associated with objects?

• functions are hardly used in OOP

• each object can have only one function associated with it

• functions renamed as a methods, represent behavior of objects

• functions always get declared outside the object and can't be part of it

Answer explanation

In OOP, functions are typically called methods and are tied to objects. They define what actions can be performed on or by these objects. In OOP, methods (functions in OOP) are usually declared inside the object, allowing them to directly access and manipulate the object's data. An object can have multiple methods associated with it, allowing it to perform a variety of actions. Functions, known as methods in an object-oriented context, play a crucial role in OOP. They define the behaviors of objects.