C Language Q&A
- Home
- / Python Handay
- / C Language Q&A
- What is C?
A high-level programming language known for its efficiency and control over system resources. - What is a pointer?
A variable that stores the memory address of another variable. - What is the difference between ++i and i++?
++i increments i before its value is used; i++ increments after its value is used. - What is a function?
A block of code that performs a specific task and can be reused. - What is the difference between call by value and call by reference?
Call by value passes a copy of the variable; call by reference passes the variable’s address. - What are arrays?
A collection of elements of the same data type stored in contiguous memory locations. - What is a structure?
A user-defined data type that groups related variables of different data types. - What is a union?
Similar to a structure but only one member can hold a value at a time. - What is a string in C?
An array of characters terminated by a null character (\0). - What is the purpose of #include?
It is a preprocessor directive that includes header files in a program. - What is dynamic memory allocation?
Allocating memory at runtime using functions like malloc(), calloc(), and free(). - What is a memory leak?
When allocated memory is not deallocated, leading to wasted resources. - What is the difference between malloc() and calloc()?
malloc() allocates uninitialized memory; calloc() allocates zero-initialized memory. - What is the purpose of free()?
It deallocates previously allocated memory. - What is a loop?
A control structure that repeats a block of code multiple times. - What are the types of loops in C?
for, while, and do-while loops. - What is an if statement?
A conditional statement that executes a block of code if a specified condition is true. - What is a switch statement?
A multi-way branch statement that executes code based on the value of a variable. - What is a break statement?
It exits the nearest enclosing loop or switch statement. - What are operators?
Symbols that perform operations on variables and values. - What is the difference between == and =?
== is a comparison operator; = is an assignment operator. - What are logical operators?
Operators that return true or false based on logical expressions (&&, ||, !). - What is the modulus operator?
The % operator returns the remainder of a division operation. - What is the ternary operator?
A shorthand for if-else, written as condition ? expr1 : expr2 - What is recursion?
A function that calls itself to solve a problem. - What is a header file?
A file containing function declarations and macro definitions, usually with a .h extension. - What is the main() function?
The entry point of a C program where execution begins. - What is a macro?
A preprocessor directive that defines a shorthand for a longer code snippet. - What is a static variable?
A variable that retains its value between function calls. - What is file handling in C?
The process of reading from and writing to files using C functions. - What are the modes of file operation?
r (read), w (write), a (append), r+ (read and write). - What is the purpose of fopen()?
To open a file and return a file pointer. - What is the purpose of fclose()?
To close an open file. - What are fprintf() and fscanf()?
Functions used for formatted writing to and reading from files. - What is the purpose of typedef?
To create an alias for a data type. - What is the difference between struct and union?
struct can store multiple data types, while union can store only one at a time. - What is the volatile keyword?
A keyword that tells the compiler that a variable may be changed by something outside the control of the code. - What is the difference between fgets() and gets()?
fgets() is safer and can limit input size; gets() can lead to buffer overflow. - What is a dangling pointer?
A pointer that points to a memory location that has been deallocated.
- What is the difference between a local and global variable?
A local variable is declared within a function and cannot be accessed outside; a global variable is accessible throughout the program. - What are the valid identifiers in C?
Identifiers must begin with a letter or underscore and can contain letters, digits, and underscores. - What is a function prototype?
A declaration of a function that specifies its name, return type, and parameters without defining its body. - What is inline function?
A function that is expanded in line when called, used for small, frequently called functions. - What is a preprocessor?
A tool that processes source code before compilation, handling directives like #include and #define. - What are comments in C?
Text in the code ignored by the compiler, used for explanations. Syntax: // for single-line, /*…*/ for multi-line. - What is the purpose of const keyword?
To define a constant variable whose value cannot be changed. - What is modularization?
Dividing a program into smaller modules to improve clarity and manageability. - What are best practices for writing C code?
Use comments, follow naming conventions, avoid global variables, and modularize code. - What is the difference between struct and enum?
struct groups variables of different types; enum defines a set of named integer constants. - What is type casting?
Converting a variable from one data type to another. - What is a null pointer?
A pointer that does not point to any memory location or object. - What is a default argument?
A value that a function parameter assumes if no argument is passed. - What is the purpose of main() returning an integer?
To indicate the success or failure of the program to the operating system.
