Question

Which of the following are not valid cout statements? A) cout \(<<\) "Hello world" B) cout \(<<\) Hello world; C) cout \(<<\) "Hello" \(<<\) " world"

Short answer

A: cout << "Hello world" B: cout << Hello world; C: cout << "Hello" << " world" Answer: B

Step-by-step solution

Understanding cout syntax

To understand the proper syntax for the cout statement in C++, note that it makes use of the insertion operator << and quotes are essential when directly outputting a string.

Analyzing Option A

The cout statement is `cout << "Hello world"`. The syntax appears correct; there are double quotes around the string "Hello world" and the insertion operator << is used. This is a validcout statement.

Analyzing Option B

The cout statement is `cout << Hello world;`. There are no double quotes around the string "Hello world". The absence of quotes makes this statement invalid.

Analyzing Option C

The cout statement is `cout << "Hello" << " world"`. There are double quotes around the two individual strings "Hello" and " world". The insertion operator << is used, and it is valid to chain multiple << operators together. This is a valid coutstatement.

Conclusion

Option B is not a valid cout statement due to the lack of double quotes around the string "Hello world". Options A and C are both valid cout statements.