Streams

Standard IO streams in C++ STL

This is a medium-difficulty language-knowledge question that tests your familiarity with the C++ standard library's input/output infrastructure. It requires recall of which predefined stream objects the <iostream> header automatically instantiates and makes available without additional setup.

Questions like this appear in technical screens because they separate candidates who have worked with C++ in practice from those who have only read about it. The question focuses on the narrow set of standard streams—excluding their wide-character variants—that any C++ programmer is expected to know by name and purpose.

• The <iostream> header and global object instantiation
• Standard input, output, and error streams
• Distinction between narrow and wide stream variants