Identifier vs. Variable: What's the Difference?
Edited by Aimie Carlson || By Janet White || Published on February 2, 2024
An identifier is a name given to elements in a program, like variables, functions, arrays, etc., while a variable is a storage location paired with an associated symbolic name, which contains some known or unknown quantity or information.
Key Differences
An identifier in programming is a symbolic name given to various elements like variables, functions, classes, and arrays. It serves as a way to identify these elements uniquely within the program. A variable, on the other hand, is a specific type of identifier that represents a memory location in which data is stored. While all variables are identifiers, not all identifiers are variables.
Identifiers are chosen names used to differentiate and reference various programming elements. They follow specific naming rules and conventions in programming languages. Variables, as a subset of identifiers, not only have a name but also are associated with a particular data type and hold a value. This value can change over time, hence the term "variable."
In terms of scope, identifiers can have different levels of visibility in a program, such as local, global, or class-level. Variables, as identifiers, inherit these scope properties, determining where they are accessible and modifiable within the code. This concept is crucial for managing data and preventing conflicts in larger programs.
When considering usage, identifiers are integral in making the code readable and understandable. They provide a way of labeling data and functions with meaningful names. Variables, specifically, are used to manipulate and store data, serving as the backbone for data handling in programming.
The naming of identifiers, including variables, is vital for effective programming. Good naming conventions make code maintainable and easier to understand. While variables are essentially for storing and retrieving data, their identifiers should accurately reflect their purpose and usage in the program.
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Comparison Chart
Definition
A name given to elements like functions, arrays, etc.
A storage location with an associated name.
Nature
Symbolic name.
Data holder.
Types of Elements
Can represent functions, classes, constants, etc.
Specifically represents data storage.
Role in Programming
Identification and differentiation.
Data manipulation and storage.
Naming Rules
Must follow language-specific conventions.
Inherits identifier naming rules.
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Example
FunctionName, className
Age, totalAmount
Identifier and Variable Definitions
Identifier
A name given to programming elements.
In int total = 0;, total is an identifier for a variable.
Variable
Holder of changeable data in a program.
Float salary = 5000.00; Here, salary is a variable that can be updated.
Identifier
Symbolic representation in code.
In void calculateSum(), calculateSum is an identifier for a function.
Variable
A named unit in code storing information.
Bool isComplete = false; Here, isComplete is a variable storing a boolean value.
Identifier
Marker for arrays, objects in programming.
In int numbers[10];, numbers is an identifier for an array.
Variable
A storage location with an associated name.
Int age = 25; Here, age is a variable holding the value 25.
Identifier
Name assigned to constants, variables, functions.
In const PI = 3.14;, PI is an identifier for a constant.
Variable
Data element with variable content.
Double temperature = 98.6; Here, temperature is a variable for storing numerical data.
Identifier
Unique label for various code components.
In class Car { }, Car is an identifier for a class.
Variable
Represents values that can be modified.
String name = John; Here, name is a variable containing a string.
Identifier
(HTML) A code that distinguishes a particular element from all other elements in a document.
Variable
(programming) A named memory location in which a program can store intermediate results and from which it can read them.
Identifier
(databases) A primary key.
FAQs
What is an identifier?
A name given to programming elements like functions, variables, classes.
Are all identifiers variables?
No, identifiers can also be function names, class names, etc.
Is 'main' in C++ an identifier or a variable?
It's an identifier, specifically for the main function.
How do identifiers and variables differ in usage?
Identifiers refer to any named element, while variables specifically store data.
What is a variable?
A storage location in a program associated with a symbolic name.
Can a variable name be any identifier?
Yes, but it must adhere to specific naming rules of the programming language.
Can two functions have the same identifier?
No, function identifiers must be unique within the same scope.
Are variables always changeable?
Generally, yes, but const variables can hold constant values.
What's an example of a variable?
In int count = 10;, count is a variable.
Can identifiers include numbers?
Yes, but they cannot start with a number.
Are variables only used for numerical data?
No, they can store various data types, including strings and booleans.
What's an example of an identifier that's not a variable?
sqrt in sqrt(4) is an identifier for a function, not a variable.
Do variables affect program performance?
Improper use of variables, like excessive global variables, can affect performance.
Can the same identifier be used for different elements?
No, identifiers must be unique within their scope.
Do variables retain their value after program execution?
No, they lose their value once the program terminates.
Can identifiers be renamed easily?
Yes, but all references to them in the code must also be updated.
How do identifiers help in programming?
They make the code more readable and manageable.
What is the scope of a variable?
The area in the code where the variable is accessible and modifiable.
Is case sensitivity important for identifiers and variables?
Yes, in many programming languages, they are case-sensitive.
Can a variable exist without an identifier?
No, a variable must have an identifier to be referenced and used in the program.
About Author
Written by
Janet WhiteJanet White has been an esteemed writer and blogger for Difference Wiki. Holding a Master's degree in Science and Medical Journalism from the prestigious Boston University, she has consistently demonstrated her expertise and passion for her field. When she's not immersed in her work, Janet relishes her time exercising, delving into a good book, and cherishing moments with friends and family.
Edited by
Aimie CarlsonAimie Carlson, holding a master's degree in English literature, is a fervent English language enthusiast. She lends her writing talents to Difference Wiki, a prominent website that specializes in comparisons, offering readers insightful analyses that both captivate and inform.
