Free Test Scope and lifetime of ... – C Language

Q1: What is the primary purpose of the extern keyword in C?

A. To define a variable B. To declare a variable without defining it C. To initialize a variable D. To create a local variable

Q2: Where is an extern variable typically stored?

A. Stack B. Heap C. Data segment D. Register

Q3: What is the lifetime of an extern variable in C?

A. Until the end of the block B. Until the program terminates C. Until the function returns D. Until the file is closed

Q4: Which of the following is true about extern variables?

A. They have block scope B. They have file scope C. They have function scope D. They have register scope

Q5: Can extern variables be initialized inside a function?

A. Yes, always B. No, never C. Only once in the entire program D. Only if declared static

Q6: What happens if you declare a variable with extern but do not define it anywhere?

A. Compiler error B. Runtime error C. It is initialized to zero D. It is created dynamically

Q7: Which storage class must be used with extern variables?

A. auto B. static C. extern D. register

Q8: Can an extern variable be accessed in multiple source files?

A. Yes B. No C. Only if it is static D. Only if it is constant

Q9: Where is the definition of an extern variable placed?

A. In the header file B. In exactly one source file C. In every source file D. Inside a function

Q10: What is the default value of an uninitialized extern variable?

A. Garbage value B. 0 C. Depends on compiler D. Undefined

Q11: What is the correct way to declare an extern integer variable?

A. extern int x; B. int extern x; C. extern x int; D. int x extern;

Q12: When should extern be used in C?

A. When defining variables B. When declaring variables defined elsewhere C. When creating constants D. When making local variables

Q13: Can extern variables be declared inside a block?

A. Yes, but they still have global scope B. No C. Only in header files D. Only in main function

Q14: What is the scope of an extern variable?

A. Function scope B. Block scope C. File or global scope D. Register scope

Q15: What is the difference between extern and static variables in C?

A. Extern has local scope, static has global scope B. Extern has global scope, static limits scope to the file C. Both have same scope D. Static variables can be used across files

Q16: Do extern variables occupy memory?

A. Yes, when defined B. No C. Only in stack D. Only in heap

Q17: Which keyword is used to declare a variable in another file?

A. static B. extern C. register D. const

Q18: If a variable is declared extern multiple times in different files, how many copies are created?

A. One B. Two C. Depends on compiler D. Unlimited

Q19: Which section of memory holds extern variables?

A. Code segment B. Stack C. Data segment D. Heap

Q20: Can an extern variable be constant?

A. Yes B. No C. Only in header files D. Only if initialized

Quiz for Scope and lifetime of variables extern