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Questions and Answers
What is the built-in data type for Boolean values in C?
What is the built-in data type for Boolean values in C?
What is the correct syntax to declare multiple variables of the same data type in C?
What is the correct syntax to declare multiple variables of the same data type in C?
What is the purpose of initialization in C?
What is the purpose of initialization in C?
What is the scope of a variable declared inside a function in C?
What is the scope of a variable declared inside a function in C?
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What is the difference between declaration and initialization in C?
What is the difference between declaration and initialization in C?
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Study Notes
Data Types
- C has several built-in data types:
- Integers:
int
,short
,long
,unsigned int
, etc. - Floating-point numbers:
float
,double
,long double
- Characters:
char
- Boolean: No built-in type, but often represented using
int
(0 for false, 1 for true) - Void:
void
(no value)
- Integers:
Declaration
- A variable must be declared before it can be used
- Declaration syntax:
data_type variable_name;
- Example:
int x;
- Example:
- Multiple variables can be declared in a single statement, separated by commas
- Example:
int x, y, z;
- Example:
Assignment
- Assignment operator:
=
- Syntax:
variable_name = value;
- Example:
x = 10;
- Example:
- Assignment can be done at declaration time or later in the code
Initialization
- Initialization is a combination of declaration and assignment
- Syntax:
data_type variable_name = value;
- Example:
int x = 10;
- Example:
- Initialization is optional, but recommended to avoid undefined values
Scope
- Scope refers to the region of the code where a variable is accessible
- Variables have one of the following scopes:
- Local: Variables declared inside a function or block, accessible only within that scope
- Global: Variables declared outside all functions, accessible from any function
- Static local: Variables declared inside a function, but retain their value between function calls
- External: Variables declared in one file, accessible from other files
Data Types
- C has several built-in data types, including integers, floating-point numbers, characters, and void.
- Integers can be
int
,short
,long
, orunsigned int
. - Floating-point numbers can be
float
,double
, orlong double
. - The character data type is
char
. - Boolean is not a built-in type, but often represented using
int
(0 for false, 1 for true). - The
void
data type has no value.
Declaration
- A variable must be declared before it can be used.
- The declaration syntax is
data_type variable_name;
. - Multiple variables can be declared in a single statement, separated by commas.
Assignment
- The assignment operator is
=
. - The assignment syntax is
variable_name = value;
. - Assignment can be done at declaration time or later in the code.
Initialization
- Initialization is a combination of declaration and assignment.
- The initialization syntax is
data_type variable_name = value;
. - Initialization is optional, but recommended to avoid undefined values.
Scope
- Scope refers to the region of the code where a variable is accessible.
- Variables have one of four scopes: local, global, static local, or external.
- Local variables are declared inside a function or block and are only accessible within that scope.
- Global variables are declared outside all functions and are accessible from any function.
- Static local variables are declared inside a function, but retain their value between function calls.
- External variables are declared in one file and are accessible from other files.
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Description
Learn about the built-in data types in C programming, including integers, floating-point numbers, characters, and more. Understand how to declare variables in C.