Question 1

Which of the following is not a valid variable name declaration?
A)int __a3;
B)int __3a;
C)int __A3;
D)None of the mentioned

Accepted Answer

All the given options are valid variable names in many programming languages, including C and C++. Identifiers can begin with an underscore followed by digits, letters, or a combination thereof.

Question 2

Which of the following is not a valid variable name declaration?
A)int _a3;
B)int a_3;
C)int 3_a;
D)int _3a

Accepted Answer

Variable names cannot begin with a number, making "3_a" an invalid variable name according to the naming conventions in most programming languages, including C and Java.

Question 3

Why do variable names beginning with the underscore is not encouraged?
A)It is not standardized
B)To avoid conflicts since assemblers and loaders use such names
C)To avoid conflicts since library routines use such names
D)To avoid conflicts with environment variables of an operating system

Accepted Answer

Variable names beginning with an underscore are often used by library routines and system-level code, so using them in user code can lead to conflicts and unexpected behavior.

Question 4

All keywords in C are in ____________
A)LowerCase letters
B)UpperCase letters
C)CamelCase letters
D)None of the mentioned

Accepted Answer

All keywords in C, such as int, return, or if, are written in lowercase letters.

Question 5

Variable name resolution (number of significant characters for the uniqueness of variable) depends on ___________
A)Compiler and linker implementations
B)Assemblers and loaders implementations
C)C language
D)None of the mentioned

Accepted Answer

Variable name resolution and the number of significant characters that are considered for the uniqueness of a variable name depend on the compiler and linker implementations. Different compilers may have different limits on the number of characters they consider significant in identifiers.

Question 6

Which of the following is not a valid C variable name?
A)int number;
B)float rate;
C)int variable_count;
D)int $main;

Accepted Answer

In C, variable names cannot begin with a dollar sign ($). They must start with a letter (either uppercase or lowercase) or an underscore.

Question 7

Which of the following is true for variable names in C?
A)They can contain alphanumeric characters as well as special characters
B)It is not an error to declare a variable to be one of the keywords(like goto, static)
C)Variable names cannot start with a digit
D)Variable can be of any length

Accepted Answer

Variable names in C must start with a letter (either uppercase or lowercase) or an underscore (_), but not with a digit. This is why option C is correct. Options A, B, and D are incorrect because: A) Variable names cannot contain special characters except for the underscore (_), B) Using keywords as variable names is not allowed and will result in a compilation error, and D) There is a limit to the length of variable names that the C compiler will recognize, typically 31 characters for many compilers, though the standard only requires compilers to recognize the first 63 characters for external names and 31 for internal names.

Question 8

What is short int in C programming?
A)The basic data type of C
B)Qualifier
C)Short is the qualifier and int is the basic data type
D)All of the mentioned

Accepted Answer

Short is a qualifier that modifies the basic data type int to specify a smaller range of numbers.

Question 9

The format identifier '%i' is also used for _____ data type.
A)char
B)int
C)float
D)double

Accepted Answer

The format identifier '%i' is used for the integer data type in C programming and similar languages, allowing for input and output of integer values.

Question 10

Which data type is most suitable for storing a number 65000 in a 32-bit system?
A)signed short
B)unsigned short
C)long
D)int

Accepted Answer

An unsigned short can store values from 0 to 65535, which is suitable for storing the number 65000.

Question 11

Which of the following is a User-defined data type?
A)typedef int Boolean;
B)typedef enum {Mon, Tue, Wed, Thu, Fri} Workdays;
C)struct {char name[10], int age};
D)all of the mentioned

Accepted Answer

All the mentioned options are examples of user-defined data types in C. "typedef" is used to create a new name for an existing type, "enum" defines a new enumeration type, and "struct" defines a structure type.

Question 12

What is the size of an int data type?
A)4 Bytes
B)8 Bytes
C)Depends on the system/compiler
D)Cannot be determined

Accepted Answer

The size of an int data type can vary depending on the system or compiler being used. Typically, it is 4 bytes on a 32-bit system and can be different on other architectures.

Question 13

enum types are processed by _________
A)Compiler
B)Preprocessor
C)Linker
D)Assembler

Accepted Answer

Enum types are processed by the compiler, as they are part of the high-level language syntax that gets compiled into machine code. Enums are used to define named constants, which the compiler needs to understand and translate accordingly.

Question 14

Which of the following statement is false?
A)Constant variables need not be defined as they are declared and can be defined later
B)Global constant variables are initialized to zero
C)const keyword is used to define constant values
D)You cannot reassign a value to a constant variable

Accepted Answer

A is false because constant variables must be initialized at the time of their declaration; they cannot be defined later.

Question 15

Which of the following declaration is not supported by C?
A)String str;
B)char *str;
C)float str = 3e2;
D)Both String str; & float str = 3e2;

Accepted Answer

C is a low-level language that does not have a built-in String type; it uses character arrays or character pointers to handle strings.

Question 16

Which of the following declaration is illegal?
A)char *str = "string Contents";
B)char str[] = "string Contents"";
C)char str[20] = "string Contents"";
D)char[] str = "string Contents"";

Accepted Answer

char[] is not a valid declaration in C.

Question 17

Which keyword is used to prevent any changes in the variable within a C program?
A)immutable
B)mutable
C)const
D)volatile

Accepted Answer

The keyword "const" is used in C programming to declare a variable as constant, which means its value cannot be altered throughout the program.

Question 18

Which of the following is not a pointer declaration?
A)char a[10];
B)char a[] = {'1', '2', '3', '4'};
C)char *str;
D)char a;

Accepted Answer

A pointer declaration reserves memory for a pointer variable, which stores the address of another variable. In option D, 'char a;' declares a character variable 'a', not a pointer.

Question 19

Which of the following statement is false?
A)A variable defined once can be defined again with different scope
B)A single variable cannot be defined with two different types in the same scope
C)A variable must be declared and defined at the same time
D)A variable refers to a location in memory

Accepted Answer

Variables in many programming languages can be declared first and then defined at a later point in the code, meaning they do not have to be declared and defined simultaneously. This allows for more flexible code structure and variable management.

Question 20

A variable declared in a function can be used in main().
A)True
B)False
C)True if it is declared static
D)None of the mentioned

Accepted Answer

A variable declared in a function (local variable) has scope only within that function and cannot be accessed directly from main() or any other function unless it is passed as an argument or otherwise made accessible (e.g., through pointers, global variables, or static declaration). Static does not change the scope, only the lifetime of the variable.

Quiz 1: Introduction to C Language

Which of the following is not a valid variable name declaration?

Which of the following is not a valid variable name declaration?

Why do variable names beginning with the underscore is not encouraged?

All keywords in C are in ____________

Variable name resolution (number of significant characters for the uniqueness of variable) depends on ___________

Which of the following is not a valid C variable name?

Which of the following is true for variable names in C?

What is short int in C programming?

The format identifier '%i' is also used for _____ data type.

Which data type is most suitable for storing a number 65000 in a 32-bit system?

Which of the following is a User-defined data type?

What is the size of an int data type?

enum types are processed by _________

Which of the following statement is false?

Which of the following declaration is not supported by C?

Which of the following declaration is illegal?

Which keyword is used to prevent any changes in the variable within a C program?

Which of the following is not a pointer declaration?

Which of the following statement is false?

A variable declared in a function can be used in main() .