In computer programming, a variable is
A A value that changes each time a program runs.
B A fixed placeholder in the code that can be assigned a value.
C An uncertainty that cannot be determined in advance.
D A description of the variance across different user’s hardware and operating systems.
E An instruction left for the computer to decide how to interpret.
The correct answer and explanation is:
The correct answer is B: A fixed placeholder in the code that can be assigned a value.
In computer programming, a variable is essentially a container used to store data that can be changed during the execution of the program. It is given a name, which is used to reference the data stored within it. The data or value assigned to a variable can vary depending on the program’s flow or user input.
When you define a variable, you create a placeholder in memory where you can store information like numbers, text, or other types of data. The variable itself doesn’t hold a fixed value; instead, it holds a reference to the data that can change as the program runs. For example, in a program calculating the sum of numbers, a variable might hold the sum, and as numbers are added, the value stored in the variable will update accordingly.
Variables are essential in programming because they allow for flexibility and dynamic behavior. Without variables, it would be impossible to create programs that can perform different tasks or handle different inputs. They are fundamental in all programming languages, and their use allows programmers to write code that is reusable and adaptable.
Variables have certain properties, such as the data type (e.g., integer, string, boolean), which determines what kind of data the variable can store. The type of a variable helps the programming language understand how to process the data stored in that variable.
In short, a variable is a fundamental concept in programming that enables the storage, manipulation, and retrieval of data, and its value can change throughout the program’s execution.