(Write \(C++\) Statements) Write a statement for each of the following: a) Print integer 40000 left justified in a 15 -digit field. b) Read a string into character array variable state. c) Print 200 with and without a sign. d) Print the decimal value 100 in hexadecimal form preceded by \(0 x\). e) Read characters into array charArray until the character 'p' is encountered, up to a limit of 10 characters (including the terminating null character). Extract the delimiter from the input stream, and discard it. f) Print 1.234 in a 9 -digit field with preceding zeros.

In C++, input and output operations are critical for program interaction with users and external sources. These operations are managed by the standard I/O streams - cin for input and cout for output. Understanding how to manipulate these streams for different types of data is essential for effective communication between a program and its environment.

Through the use of cin, you can extract values from the input, while cout helps you print information back to the user. By leveraging stream manipulators and formatted I/O functions, C++ provides programmers with powerful tools for controlling input and output in a manner that suits the needs of their application.

For instance, managing how integers are displayed or controlling the precision of floating-point values are tasks C++ handles with ease. Whether you're reading strings into character arrays or handling hexadecimal numbers, mastering these concepts is fundamental for all aspiring C++ developers.

Stream manipulators in C++ are special functions that modify how data is read from or written to streams, allowing us to format I/O operations. Some common manipulators from the <iomanip> header file include std::setw for setting field width, std::left and std::right for alignment, std::setfill for padding, and std::hex or std::decimal for base formatting.

For example, to print the integer 40000 left-justified in a 15-digit field, as stated in the exercise, the manipulators std::left and std::setw play a vital role. Similarly, manipulators like std::showpos and std::noshowpos control the display of the sign for numeric values. Utilizing these manipulators correctly not only enhances the readability of output but also ensures data is presented in the format required by your program's logic.

Character arrays in C++ are a way to store sequences of characters, acting as strings before the introduction of the std::string class. They require careful handling, especially when it comes to I/O operations, to avoid buffer overflows and manage the null terminator that indicates the end of the string.

Reading strings into char arrays typically involves functions like std::cin.getline(), which reads a stream of characters until a newline character is encountered or a specified limit is reached. This function automatically adds the null terminator, making sure the character array is properly formatted as a C-string.

Additionally, character arrays are often manipulated using loops and conditional statements, especially when the input needs to be checked or modified before storage – as demonstrated by the exercise where characters are read into an array until a 'p' is encountered. This requires a fine understanding of how C++ handles characters and how to efficiently use array indexing to manage such operations.