Section H PC Quiz 1

The correct way of variable declaration is A_B. Variable names can only contain letters, numbers, and underscores, and must start with a letter or an underscore. The option 1A_B is incorrect because it starts with a number. The option "if" is incorrect because it is a reserved keyword in most programming languages and cannot be used as a variable name. The option AB@3 is incorrect because it contains a special character (@) which is not allowed in variable names.

The correct answer is "const". In programming, the keyword "const" is used to define a constant variable. A constant variable is a value that cannot be changed once it is assigned. By using the "const" keyword, the programmer can ensure that the value of the variable remains constant throughout the program.

The declaration "unsigned u" indicates that the variable "u" is an unsigned integer. The keyword "unsigned" is used to specify that the variable can only hold non-negative values and increases the range of positive values that can be stored. Therefore, "u" can store only positive integers or zero, and cannot hold negative values or characters.

The purpose of the program fragment is to exchange (swap) the contents of s and b. This is achieved by using a temporary variable to store the value of one variable while the values of both variables are being swapped. The first line of code assigns the sum of s and b to b, effectively storing the value of s in b. The second line of code assigns the difference between b and s to s, which swaps the values of s and b. Finally, the third line of code assigns the difference between b and s to b, effectively storing the original value of b in s.

The variable name "double" is invalid because it is a reserved keyword in many programming languages, including Java and C++. Reserved keywords have a special meaning in the language and cannot be used as variable names.

The absence of the "&" symbol before the variable "x" in the scanf() function will cause an error. The "&" symbol is used to pass the address of the variable to the function, allowing it to directly modify the value stored at that address. Without the "&" symbol, the function will not be able to access the memory location of the variable, resulting in an error.

The correct answer is "a=b=c=8;" because in C programming, multiple variables can be assigned the same value in a single statement. This statement assigns the value 8 to variables a, b, and c simultaneously.

The variable name "Id No" is incorrect because it contains a space, which is not allowed in variable names. Variable names should not have spaces or special characters, and should be written in a way that is clear and meaningful.

The expression "a=5/2" assigns the value of the division 5/2 to the variable 'a'. In integer division, the result is the quotient without any decimal places. Therefore, the result of 5/2 is 2, and this value will be assigned to 'a'.

The symbol "%d" is a format specifier. In programming, format specifiers are used to define the type and format of data that should be printed or read. In this case, "%d" is used to format and print an integer value.

The variable name "number" is valid because it starts with a letter, which is a requirement for variable names in most programming languages. Additionally, it does not contain any special characters or symbols, and it consists of only alphanumeric characters.

There are 32 keywords in the C Language. Keywords are reserved words that have a specific meaning in the programming language and cannot be used as variable names or identifiers. These keywords are predefined and have a specific purpose in the C Language syntax.

The correct answer is "Relational." Relational operators are used to compare two values and determine the relationship between them, such as whether one value is equal to, greater than, or less than the other. These operators include symbols like == (equal to), != (not equal to), > (greater than), = (greater than or equal to), and

The variable name "row_1" is valid because it follows the rules for naming variables. In most programming languages, variable names can only contain letters, numbers, and underscores. They cannot start with a number or contain any special characters or spaces. "row_1" satisfies these requirements and is therefore a valid variable name.

The correct sequence of steps to run a program is to first write the code, then compile it to convert it into machine-readable instructions, followed by linking the compiled code with any necessary libraries or dependencies. After that, the program is loaded into memory, and finally, it is executed or run.

The correct answer is "break". In the C language, "break" is a reserved keyword that is used to terminate a loop or switch statement. It is used to exit a loop prematurely when a certain condition is met or to exit a switch statement after a specific case is executed. The use of "break" as a variable or function name is not allowed in C as it is reserved for this specific purpose.

The code snippet `printf("%d", 0&&4);` uses the logical AND operator (`&&`) to evaluate the expression `0&&4`. In this case, the expression evaluates to `0` because both operands are non-zero values. According to the rules of the logical AND operator, if any of the operands is `0`, the result is `0`. Therefore, the output of the `printf` statement will be `0`.

Machine language does not need any translator because it is the lowest-level programming language that can be directly understood and executed by a computer's hardware. It consists of binary code instructions that are specific to the computer's architecture. As a result, no translation or interpretation is required for the computer to understand and execute the instructions in machine language.

The operator "&" is used for performing a bitwise AND operation. Bitwise AND compares the corresponding bits of two numbers and returns a new number where each bit is set to 1 only if both corresponding bits in the original numbers are 1. This operator is commonly used in programming to manipulate individual bits within binary numbers.

The given code calculates the bitwise XOR of 15 and 13, which results in 2. The XOR operation compares the corresponding bits of two numbers and returns 1 if they are different, and 0 if they are the same. In this case, the binary representation of 15 is 1111 and the binary representation of 13 is 1101. When performing the XOR operation, the bits that are different are set to 1, resulting in the binary representation of 2, which is 0010. Therefore, the value of variable 'a' is 2, and when printed using printf, it will display 2.

The given answer is "arithmetic, relational, assignment". In an expression without specified parentheses, the arithmetic operators are evaluated first, followed by the relational operators, and finally the assignment operators. This order ensures that any necessary calculations are performed before making comparisons and assigning values to variables.

The constant "float" can be expressed both in fractional and exponential forms. In fractional form, it represents a decimal number with a fractional part, such as 3.14. In exponential form, it can be expressed as a number multiplied by a power of 10, such as 3.14 x 10^1. This flexibility allows for greater precision and a wider range of values compared to other data types like "char", "void", and "int".

The valid variable name in this case is "Floats". Variable names can consist of letters, numbers, and underscores, but they cannot start with a number or contain special characters like "+". "Initial.Name" is not a valid variable name because it contains a dot, which is not allowed. "$ABC" is also not a valid variable name because it starts with a special character. Therefore, the correct answer is "Floats".

The format identifier '%i' is commonly used for the int data type. This format specifier is used in C programming to display or read integer values. It is used with functions like printf() and scanf() to format the output or input of integer values.

The correct answer is that the value of b is assigned to variable a but if b changes later, it will not affect the value of variable a. This is because in an assignment statement, the value of the variable on the right side of the assignment operator (=) is assigned to the variable on the left side. However, any changes made to the variable on the right side after the assignment will not affect the value of the variable on the left side.

The code defines a macro function ISEQUAL that takes two arguments X and Y and checks if X is equal to Y using the equality operator ==. In the main function, variables X and Y are declared. The printf statement prints the result of calling the ISEQUAL macro function with X as the first argument and 1 as the second argument. Since X is not initialized, its value is undefined, and the result of the comparison will be unpredictable. Therefore, the output could be any value, but it is most likely to be 0.

An external variable is a variable that is declared outside of any function and is accessible by all functions in a program. It has a global scope, meaning it can be accessed from anywhere in the program. If an external variable is not explicitly initialized, it will automatically be initialized to 0. Therefore, the correct answer is that an external variable is globally accessible by all functions, has a declaration, and will be initialized to 0 if not initialized.

The correct answer is 32 because the sizeof() operator in C++ returns the size in bytes of the data type or variable specified. In this case, the data type is long int, which typically has a size of 4 bytes on most systems. Therefore, the output of sizeof(long int) will be 32 bits.

In the 'C' language, double, char, and float are all primitive data types. However, array is not a primitive data type in 'C'. An array is a collection of elements of the same data type, and it is considered a derived data type in 'C'.

Relational operators are used to compare the values of operands in C language. These operators compare two values and return a logical value (true or false) based on the comparison. Examples of relational operators in C include equal to (==), not equal to (!=), greater than (>), less than (=), and less than or equal to (

The conditional or ternary operator is used to check a condition and select a value based on the result of that condition. It allows for concise and efficient code by providing a shorthand way to write if-else statements. The operator consists of a condition followed by a question mark, then a value to be returned if the condition is true, and a colon followed by a value to be returned if the condition is false. This operator is commonly used in programming languages like C, C++, and Java.

The ternary operator is a conditional operator that takes three operands. It is represented by the symbol "?:". The first operand is a condition, the second operand is the value returned if the condition is true, and the third operand is the value returned if the condition is false. Therefore, the correct answer is ?: as it represents the ternary operator.

The result of a relational operator can be either true or false, depending on the comparison being made. For example, if we compare two numbers using the greater than operator, the result will be true if the first number is indeed greater than the second number, and false otherwise. Similarly, if we compare two strings using the equal to operator, the result will be true if the two strings are equal, and false otherwise. Therefore, the correct answer is "True OR False" because the result of a relational operator can be either true or false.

In this code snippet, the variable x is initially assigned the value 23. Then, the post-decrement operator (--) is used to decrement the value of x by 1. However, since the post-decrement operator is used, the value of x is first assigned to y and then decremented. Therefore, the value of y remains 23. Finally, the printf statement prints the values of x and y, which are 22 and 23 respectively.

The expression "5 && 4" is a logical AND operation. In C programming, the logical AND operator (&&) returns true (1) if both operands are non-zero, and false (0) otherwise. Since both 5 and 4 are non-zero, the result of the logical AND operation is true (1). Therefore, the value of the variable "a" is 1. When we use the printf function to print the value of "a", it will output "1".

The words if, else, auto, float etc. have predefined meanings in programming languages and cannot be used as variables. They are reserved words that have specific functionalities within the language. These words are commonly referred to as keywords.

The symbols "?" and ":" are called conditional operators because they are used to create conditional expressions in programming languages. These operators evaluate a condition and return one of two values based on the result of the condition. The "?" symbol is used to specify the condition, while the ":" symbol is used to separate the two possible values. This allows for concise and efficient coding of conditional statements.

The algorithm should be both precise and unambiguous. Being precise means that the algorithm should provide clear and specific instructions, leaving no room for interpretation. This ensures that the algorithm can be executed accurately and consistently. Being unambiguous means that the algorithm should have only one possible interpretation, eliminating any confusion or ambiguity in understanding the steps. By being both precise and unambiguous, the algorithm can be easily understood and implemented by both humans and computers.

After the statement "#define PI 54.453", the value of PI is defined as 54.453. Then, the statement "PI=3.141" attempts to reassign a new value to PI, which is not valid because PI is a constant defined using the #define directive. Therefore, the value of PI remains 54.453. The statement "area = 3.2*PI" calculates the area by multiplying 3.2 with the value of PI, which is 54.453. Hence, the correct option is "area = 3.2*PI".

In the passage of text, individual words and punctuation marks are known as delimiters. Delimiters are used to separate or mark the boundaries between different elements in a text, such as words or sentences. They help to identify the structure and meaning of the text by indicating where one element ends and another begins. In this context, delimiters refer to both individual words and punctuation marks that serve this purpose.

The given code snippet declares a variable 'a' of type char and assigns it the value 'a'. The printf statement is used to print the value of 'a' as an integer using the %d format specifier. In ASCII, the character 'a' has an integer value of 97. Therefore, the code will output 97.

Spaces cannot be used as identifiers independently because spaces are not allowed in variable or identifier names. In programming languages, spaces are used to separate different parts of a statement or expression. Therefore, using spaces as identifiers would result in a syntax error.

The correct answer is "0 to 65536" because an unsigned integer can only hold positive values and zero. In this case, the range is from 0 to 65536, which includes all the possible values that can be represented by an unsigned integer.

All of the given statements are correct. An identifier in programming is a name used to identify a variable, function, or any other user-defined item. It may start with an underscore, it may end with an underscore, and "IF" is a valid identifier. Identifiers in programming languages have certain rules and conventions, but these statements adhere to those rules and are therefore correct.

An identifier is a name that starts with letters or an underscore. It is used to identify variables, functions, classes, or any other user-defined item in a program. Identifiers cannot be the same as reserved keywords, which are predefined words with special meanings in the programming language. Tokens are the individual units of a program, including identifiers, keywords, operators, and literals. Therefore, the correct answer is identifiers.

The expression "3>>1" is a right shift operation in C. In this case, it means shifting the bits of the number 3 to the right by 1 position. Shifting a number to the right by 1 is equivalent to dividing it by 2. Therefore, the result of "3>>1" is 1.

The associativity of the = operator is right to left. This means that when there are multiple assignments in a single line of code, the rightmost assignment is evaluated first and then the result is assigned to the leftmost variable. For example, in the expression "a = b = c", the value of c is assigned to b first, and then the value of b is assigned to a.

The code will produce an error because "long long double" is not a valid data type in C. It seems to be a combination of two different data types, "long long" and "double", which are not allowed to be combined in this way. Therefore, the code will not compile and an error will be thrown.

The given code declares a variable 'a' and assigns it a value of 10. However, the value of 10 is not used or referenced in any way. The next line of code is 20, which means that the value 20 is the output or result of the code.

The correct answer is #define X 2. This is a valid statement because it follows the syntax for defining a constant in C programming language. The statement starts with the #define keyword, followed by the name of the constant (X in this case), and then the value assigned to the constant (2 in this case). The value assigned to the constant can be any valid expression or literal value.