Introduction To C Plus Plus — Part 1 MCQs with Explanations

The given code uses the ternary operator to evaluate a condition and print a result based on that evaluation. The code is: cout << (5 > 2) ? "True" : "False"; The expression (5 > 2) evaluates to true because 5 is greater than 2. When the condition is true , the ternary operator returns the first value after the question mark (?). In this case, it returns "True" . Therefore, the correct output of the code is True . Correct Answer: Option A: TRUE

C++ Identifiers: Naming Rules In C++, identifiers are names you give to things like variables, functions, and classes. They must follow specific rules. Rules for Valid Identifiers: 1. They can contain letters (a-z, A-Z), digits (0-9), and underscores (_). 2. They must begin with a letter or an underscore. 3. They cannot contain spaces. 4. They cannot be C++ keywords (like int , float , while , etc.). Let's Check the Options: A) _variableName : This is valid. It starts with an underscore and uses letters. B) 2ndVariable : This is invalid . Identifiers cannot start with a digit. C) variable_name@ : This is invalid . It contains the "@" symbol, which is not allowed. D) VariableName : This is valid. It starts with a letter and uses letters. Therefore, the correct answer is E, Both (B) and (C) are not valid C++ identifiers.

Reason: In C++, when the 'static' keyword is used with a global variable, it limits the scope of that variable to the file in which it is declared. Option A: Scope limited to the file is correct because a global variable declared as static can only be accessed within the file where it is defined, making it invisible to other files in the program. Option B: Can't be modified is incorrect because the 'static' keyword does not make the variable constant or immutable. It can still be modified. Option C: Retains its value between calls applies to local static variables, not global static variables. Global static variables are not related to function calls. Option D: Global scope is incorrect because the 'static' keyword specifically restricts the scope of the variable to the file, contrary to the global scope. Hence, the correct interpretation of 'static' for global variables is that it limits the scope to the file where the variable is declared.

The expression used in the code is: cout << (5 < 2) ? "True" : "False"; This line appears to use the ternary conditional operator , but due to the missing parentheses around the conditional expression, the actual precedence rules of C++ affect the output. In C++, the insertion operator << has higher precedence than the ternary operator ?: . So, the expression is interpreted as: (cout << (5 < 2)) ? "True" : "False"; Here, 5 < 2 evaluates to false (i.e., 0) So, cout << 0 is executed , which prints 0 Then the ternary operator evaluates 0 ? "True" : "False" , which returns "False", but the result is not used or printed Thus, the final output is: 0 Since "0" is not among the options but option C says 5, this indicates the question or options may be inconsistent However, assuming the intention was to demonstrate operator precedence, the correct output should be: 0, not 5. But given the provided options, none match this expected behavior correctly So, the correct answer should actually be: None of the above , but if we must choose, Option C is incorrect

Let's break down this C++ code snippet! The code is: cout << "Hello\nWorld"; cout is used to display output on the screen. The double quotes " " enclose a string of characters that will be printed. Inside the string, we have "Hello\nWorld" . The important part here is \n . This is a special character called a newline character . \n tells the program to move the cursor to the beginning of the next line. So, "Hello\nWorld" means print "Hello", then move to the next line, and then print "World". Therefore, the correct output is "Hello" on one line and "World" on the next line. Option B and C are incorrect because they only output one word. Option D is incorrect because it prints the actual '\n' character, rather than interpreting it as a newline. The correct answer is to imagine the output with Hello appearing above World . So, the best way to visualize this output is : Hello World

The given code is a basic C++ program that prints a message to the console. It includes the <iostream> header , which allows the use of input and output streams like cout . The main function is defined correctly with appropriate parameters ( int argc, char const *argv[] ), though these parameters are not used. cout<<"Hello World"; correctly outputs the text "Hello World" to the standard output. There are no syntax or runtime errors in the code , and it will compile and run successfully. Therefore, the output will be: Hello World

Explanation: Pointers in C++ are variables that hold memory addresses . They're like street addresses that tell you where a house (data) is located. We use special operators to work with these memory addresses. + (Addition): We can add a number to a pointer to move it to a different memory location. Imagine walking a few houses down the street. - (Subtraction): Similarly, we can subtract to move backward in memory (go back a few houses). * (Dereference): This is the most important pointer operator. It lets us access the data stored at the memory address held by the pointer. Think of it like going inside the house to see what's there. The division operator (/) is not directly used with pointers in the same way as addition, subtraction, or dereference. Therefore, the correct options are addition (+), subtraction (-), and dereference (*). So the answer is (D) iv

.cpp is the correct answer to “What is the extension of a C++ source file”. This question is standard in competitive examination syllabi for Introduction To C Plus Plus.

boolean is the correct answer to “Which of the following is not a fundamental data type in C++”. This question is standard in competitive examination syllabi for Introduction To C Plus Plus.

Standard input stream is the correct answer to “What does the 'cin' object in C++ represent”. This question is standard in competitive examination syllabi for Introduction To C Plus Plus.

class is the correct answer to “What keyword is used to define a class in C++”. This question is standard in competitive examination syllabi for Introduction To C Plus Plus.

new is the correct answer to “In C++, what operator is used to allocate dynamic memory”. This question is standard in competitive examination syllabi for Introduction To C Plus Plus.

// is the correct answer to “What is the syntax for a single-line comment in C++”. This question is standard in competitive examination syllabi for Introduction To C Plus Plus.

cout is the correct answer to “What function is used to output data to the console in C++”. This question is standard in competitive examination syllabi for Introduction To C Plus Plus.

<iostream> is the correct answer to “Which header file is needed to use the 'cin' and 'cout' objects in C++”. This question is standard in competitive examination syllabi for Introduction To C Plus Plus.

Inserts a new line is the correct answer to “What does the 'endl' manipulator do in C++”. This question is standard in competitive examination syllabi for Introduction To C Plus Plus.

const is the correct answer to “Which keyword is used to define a constant in C++”. This question is standard in competitive examination syllabi for Introduction To C Plus Plus.

2 is the correct answer to “What is the output of the following code: int x = 5, y = 2; cout << x / y;”. This question is standard in competitive examination syllabi for Introduction To C Plus Plus.

int* ptr is the correct answer to “What is the correct way to declare a pointer in C++”. This question is standard in competitive examination syllabi for Introduction To C Plus Plus.

: is the correct answer to “What is the keyword used for inheritance in C++”. This question is standard in competitive examination syllabi for Introduction To C Plus Plus.

size() is the correct answer to “What function is used to return the length of a string in C++”. This question is standard in competitive examination syllabi for Introduction To C Plus Plus.

Value of x is: 10 is the correct answer to “What is the output of the following code: int x = 10; cout << "Value of x is: " << x++ << endl;”. This question is standard in competitive examination syllabi for Introduction To C Plus Plus.

Size of int in bytes is the correct answer to “What is the result of the expression: sizeof(int) in C++”. This question is standard in competitive examination syllabi for Introduction To C Plus Plus.

Recursion is the correct answer to “Which C++ feature allows a function to call itself”. This question is standard in competitive examination syllabi for Introduction To C Plus Plus.

int *arr = new int[size] is the correct answer to “What is the correct syntax to dynamically allocate memory for an array of integers in C++”. This question is standard in competitive examination syllabi for Introduction To C Plus Plus.

arr[0] is the correct answer to “Which of the following is used to access the first element of an array in C++”. This question is standard in competitive examination syllabi for Introduction To C Plus Plus.

1 is the correct answer to “What is the output of the following code: cout << (5 == 5.0); in C++”. This question is standard in competitive examination syllabi for Introduction To C Plus Plus.

Exit the switch block is the correct answer to “What is the purpose of the 'break' statement in a switch-case construct in C++”. This question is standard in competitive examination syllabi for Introduction To C Plus Plus.

#include <vector> is the correct answer to “What is the correct way to include a C++ standard library header file named 'vector' in a C++ program”. This question is standard in competitive examination syllabi for Introduction To C Plus Plus.

. is the correct answer to “Which operator is used to access the member functions and variables of an object in C++”. This question is standard in competitive examination syllabi for Introduction To C Plus Plus.

2 is the correct answer to “What is the output of the following code: cout << (10 / 4); in C++”. This question is standard in competitive examination syllabi for Introduction To C Plus Plus.

int add(int a, int b) { } is the correct answer to “What is the correct syntax to define a function named 'add' that takes two integers as parameters and returns their sum in C++”. This question is standard in competitive examination syllabi for Introduction To C Plus Plus.

nullptr is the correct answer to “What does the 'new' operator return when memory allocation fails in C++”. This question is standard in competitive examination syllabi for Introduction To C Plus Plus.

int* ptr is the correct answer to “Which of the following is the correct syntax for declaring a pointer to an integer in C++”. This question is standard in competitive examination syllabi for Introduction To C Plus Plus.

Inserts a new line is the correct answer to “In C++, what is the purpose of the 'endl' manipulator”. This question is standard in competitive examination syllabi for Introduction To C Plus Plus.

Size of char in bytes is the correct answer to “What is the result of the expression: sizeof(char) in C++”. This question is standard in competitive examination syllabi for Introduction To C Plus Plus.

This function doesn't modify the object it's called on is the correct answer to “What does the 'const' keyword signify when used with a member function in a C++ class declaration”. This question is standard in competitive examination syllabi for Introduction To C Plus Plus.

* is the correct answer to “Which operator is used to dereference a pointer in C++”. This question is standard in competitive examination syllabi for Introduction To C Plus Plus.

#include <iostream> is the correct answer to “What is the correct way to include the C++ standard input/output library header file in a C++ program”. This question is standard in competitive examination syllabi for Introduction To C Plus Plus.

2 is the correct answer to “What is the output of the following code: int x = 5, y = 2; cout << x / y; in C++”. This question is standard in competitive examination syllabi for Introduction To C Plus Plus.