There were five distinct bugs. Diagnosing each was worth 4 points.

• Error message:

  Television.cpp:48: error: ISO C++ forbids declaration of 'togglePower'with no type
  	

  Diagnosis: The problem is that the signature for the togglePower() method does not explicitly specify any return type. Though this method does not return anything, it is still necessary to make this expectation explicit by declaring a void return type, making line 48 read:

  void togglePower() { powerOn = !powerOn; }
  	

• Error message:

  Television.cpp:155: error: 'number' has not been declared
  	

  Diagnosis: The problem here is that the parameter, number, specified in the signature of setChannel does not have an explicitly declared type. We can fix this by changing line 155 to read

    bool setChannel(int number)  {

• Error message:

  Television.cpp: In constructor 'Television::Television()':
  Television.cpp:39: error: 'channel' was not declared in this scope
  	

  Diagnosis: Our construtor is trying to assign a value to channel, which presumably is meant to be a data member for this instance. However no such data member was declared. We will fix this by inserting the following in the private section of the class definition.

    /** The current channel number */
    int     channel;
  

  starting at line 25 of the file.

• Error message:

  Television.cpp: In member function 'int Television::channelDown()':
  Television.cpp:140: error: expected `(' before 'powerOn'
  Television.cpp:146: error: expected `}' before 'else'
  

  (note: line numbers here reflect previous changes)

  Diagnosis: The problem here is with the original if statement. The boolean expressions defining the condition must be enclosed within parentheses in C++. Therefore, it should be written as

    if (powerOn) {

  at what is now line 140.

• Error message:

  Television.cpp: In member function 'int Television::jumpPrevChannel() const':
  Television.cpp:177: error: assignment of data-member 'Television::channel' in read-only structure
  Television.cpp:178: error: assignment of data-member 'Television::prevChan' in read-only structure

  Diagnosis: We originally declared jumpPrevChannel() as a const method. As such, its body should not alter the state of the object. Yet our body clearly does alter the state, at lines~177 and 178 of Television.cpp (the members channel and prevChannel).

  We must either change the body so as not to alter the object, or change the declaration of the function to remove the const label. In this case, the correct remedy is to remove the const label from the signature at line 173.