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一本好的VC学习书,本人就是使用这本书开始学习的vc,希望能对大家有帮助

<PRE><FONT COLOR="#0066FF">for (int x = 0; x &lt; 100; x++)
100
</FONT></PRE>

<DL>
	<DD><B>2.</B> Write a nested <TT>for</TT> loop that prints a 10x10 pattern of <TT>0</TT>s.
</DL>

<PRE><FONT COLOR="#0066FF">for (int i = 0; i&lt; 10; i++)
{
    for ( int j = 0; j&lt; 10; j++)
       cout &lt;&lt; &quot;0&quot;;
    cout &lt;&lt; &quot;\n&quot;;
}
</FONT></PRE>

<DL>
	<DD><B>3</B>. Write a <TT>for</TT> statement to count from 100 to 200 by 2s.
</DL>

<PRE><FONT COLOR="#0066FF">for (int x = 100; x&lt;=200; x+=2)
</FONT></PRE>

<DL>
	<DD><B>4.</B> Write a <TT>while</TT> loop to count from 100 to 200 by 2s.
</DL>

<PRE><FONT COLOR="#0066FF">int x = 100;
while (x &lt;= 200)
    x+= 2;
</FONT></PRE>

<DL>
	<DD><B>5.</B> Write a <TT>do...while</TT> loop to count from 100 to 200 by 2s.
</DL>

<PRE><FONT COLOR="#0066FF">int x = 100;
do
{
    x+=2;
} while (x &lt;= 200);
</FONT></PRE>

<DL>
	<DD><B>6.</B> BUG BUSTERS: What is wrong with this code?
</DL>

<PRE><FONT COLOR="#0066FF">int counter = 0
while (counter &lt; 10)
{ 
    cout &lt;&lt; &quot;counter: &quot; &lt;&lt; counter;
    counter++;
}
</FONT></PRE>

<DL>
	<DD><TT>counter</TT> is never incremented and the <TT>while</TT> loop will never
	terminate.<BR>
	<BR>
	<B>7.</B> BUG BUSTERS: What is wrong with this code?
</DL>

<PRE><FONT COLOR="#0066FF">for (int counter = 0; counter &lt; 10; counter++);
    cout &lt;&lt; counter &lt;&lt; &quot;\n&quot;;
</FONT></PRE>

<DL>
	<DD>There is a semicolon after the loop, and the loop does nothing. The programmer
	may have intended this, but if <TT>counter</TT> was supposed to print each value,
	it won't.<BR>
	<BR>
	<B>8.</B> BUG BUSTERS: What is wrong with this code?
</DL>

<PRE><FONT COLOR="#0066FF">int counter = 100;
while (counter &lt; 10)
{
    cout &lt;&lt; &quot;counter now: &quot; &lt;&lt; counter;
    counter--;
}
</FONT></PRE>

<DL>
	<DD><TT>counter</TT> is initialized to <TT>100</TT>, but the test condition is that
	if it is less than 10, the test will fail and the body will never be executed. If
	line 1 were changed to <TT>int counter = 5;</TT>, the loop would not terminate until
	it had counted down past the smallest possible <TT>int</TT>. Because <TT>int</TT>
	is <TT>signed</TT> by default, this would not be what was intended.<BR>
	<BR>
	<B>9.</B> BUG BUSTERS: What is wrong with this code?
</DL>

<PRE><FONT COLOR="#0066FF">cout &lt;&lt; &quot;Enter a number between 0 and 5: &quot;;
cin &gt;&gt; theNumber;
switch (theNumber)
{
   case 0:
         doZero();
   case 1:              // fall through
   case 2:              // fall through
   case 3:              // fall through
   case 4:              // fall through
   case 5: 
         doOneToFive();
         break;
   default:
         doDefault();
         break;
}
</FONT></PRE>

<DL>
	<DD><TT>Case 0</TT> probably needs a <TT>break</TT> statement. If it does not, it
	should be documented with a comment.
</DL>

<H3><A NAME="Heading24"></A><FONT COLOR="#000077">Day 8</FONT></H3>
<H4 ALIGN="CENTER"><A NAME="Heading25"></A><FONT COLOR="#000077">Quiz</FONT></H4>

<DL>
	<DD><B>1. What operator is used to determine the address of a variable?<BR>
	</B><BR>
	The address of operator (<TT>&amp;</TT>) is used to determine the address of any
	variable.<BR>
	<B><BR>
	2. What operator is used to find the value stored at an address held in a pointer?<BR>
	</B><BR>
	The dereference operator (<TT>*</TT>) is used to access the value at an address in
	a pointer.<BR>
	<BR>
	<B>3. What is a pointer?<BR>
	</B><BR>
	A pointer is a variable that holds the address of another variable.<BR>
	<BR>
	<B>4. What is the difference between the address stored in a pointer and the value
	at that </B>address?<BR>
	<BR>
	The address stored in the pointer is the address of another variable. The value stored
	at that address is any value stored in any variable. The indirection operator (<TT>*</TT>)
	returns the value stored at the address, which itself is stored in the pointer.<BR>
	<BR>
	<B>5. What is the difference between the indirection operator and the address of
	oper-ator?<BR>
	</B><BR>
	The indirection operator returns the value at the address stored in a pointer. The
	address of operator (<TT>&amp;</TT>) returns the memory address of the variable.<BR>
	<BR>
	<B>6. What is the difference between <TT>const int * ptrOne</TT> and <TT>int * const
	ptrTwo</TT>?<BR>
	</B><BR>
	The <TT>const int * ptrOne</TT> declares that <TT>ptrOne</TT> is a pointer to a constant
	integer. The integer itself cannot be changed using this pointer.<BR>
	The <TT>int * const ptrTwo</TT> declares that <TT>ptrTwo</TT> is a constant pointer
	to an integer. Once it is initialized, this pointer cannot be reassigned.
</DL>

<H4 ALIGN="CENTER"><A NAME="Heading26"></A><FONT COLOR="#000077">Exercises</FONT></H4>

<DL>
	<DD><B>1.</B> What do these declarations do?
	<DL>
		<DD><B><BR>
		a.</B> <TT>int * pOne;</TT><BR>
		<B>b</B>. <TT>int vTwo;</TT><BR>
		<B>c.</B> <TT>int * pThree = &amp;vTwo;</TT><BR>
		<B><BR>
		a.</B> <TT>int * pOne;</TT> declares a pointer to an integer.<BR>
		<B>b.</B> <TT>int vTwo;</TT> declares an integer variable.<BR>
		<B>c.</B> <TT>int * pThree = &amp;vTwo;</TT> declares a pointer to an integer and
		initializes it with the address of another variable.
	</DL>
	<DD><B><BR>
	2.</B> If you have an <TT>unsigned short</TT> variable named <TT>yourAge</TT>, how
	would you declare a pointer to manipulate <TT>yourAge</TT>?
</DL>

<PRE><FONT COLOR="#0066FF">unsigned short *pAge = &amp;yourAge;
</FONT></PRE>

<DL>
	<DD><B>3.</B> Assign the value <TT>50</TT> to the variable <TT>yourAge</TT> by using
	the pointer that you declared in Exercise 2.
</DL>

<PRE><FONT COLOR="#0066FF">*pAge = 50;
</FONT></PRE>

<DL>
	<DD><B>4.</B> Write a small program that declares an integer and a pointer to integer.
	Assign the address of the integer to the pointer. Use the pointer to set a value
	in the integer variable.
</DL>

<PRE><FONT COLOR="#0066FF">int theInteger;
int *pInteger = &amp;theInteger;
*pInteger = 5;
</FONT></PRE>

<DL>
	<DD><B>5.</B> BUG BUSTERS: What is wrong with this code?
</DL>

<PRE><FONT COLOR="#0066FF">#include &lt;iostream.h&gt;
int main()
{
     int *pInt;
     *pInt = 9;
     cout &lt;&lt; &quot;The value at pInt: &quot; &lt;&lt; *pInt;
return 0;
}
</FONT></PRE>

<DL>
	<DD><TT>pInt</TT> should have been initialized. More importantly, because it was
	not initialized and was not assigned the address of any memory, it points to a random
	place in memory. Assigning <TT>9</TT> to that random place is a dangerous bug.<BR>
	<BR>
	<B>6.</B> BUG BUSTERS: What is wrong with this code?
</DL>

<PRE><FONT COLOR="#0066FF">int main()
{
    int SomeVariable = 5;
    cout &lt;&lt; &quot;SomeVariable: &quot; &lt;&lt; SomeVariable &lt;&lt; &quot;\n&quot;;
    int *pVar = &amp; SomeVariable;
    pVar = 9;
    cout &lt;&lt; &quot;SomeVariable: &quot; &lt;&lt; *pVar &lt;&lt; &quot;\n&quot;;
return 0;
}
</FONT></PRE>

<DL>
	<DD>Presumably, the programmer meant to assign <TT>9</TT> to the value at <TT>pVar</TT>.
	Unfortunately, <TT>9</TT> was assigned to be the value of <TT>pVar</TT> because the
	indirection operator (<TT>*</TT>) was left off. This will lead to disaster if <TT>pVar</TT>
	is used to assign a value.
</DL>

<H3 ALIGN="CENTER"></H3>
<H3><A NAME="Heading27"></A><FONT COLOR="#000077">Day 9</FONT></H3>
<H4 ALIGN="CENTER"><A NAME="Heading28"></A><FONT COLOR="#000077">Quiz</FONT></H4>

<DL>
	<DD><B>1. What is the difference between a reference and a pointer?<BR>
	</B><BR>
	A reference is an alias, and a pointer is a variable that holds an address. References
	cannot be null and cannot be assigned to.<BR>
	<BR>
	<B>2. When must you use a pointer rather than a reference?<BR>
	</B><BR>
	When you may need to reassign what is pointed to, or when the pointer may be null.<BR>
	<BR>
	<B>3. What does <TT>new</TT> return if there is insufficient memory to make your
	<TT>new</TT> object?<BR>
	</B><BR>
	A null pointer (<TT>0</TT>).<BR>
	<BR>
	<B>4. What is a constant reference?<BR>
	</B><BR>
	This is a shorthand way of saying &quot;a reference to a constant object.&quot;<BR>
	<BR>
	<B>5. What is the difference between passing by reference and passing a reference?<BR>
	</B><BR>
	Passing by reference means not making a local copy. It can be accomplished by passing
	a reference or by passing a pointer.
</DL>

<H4 ALIGN="CENTER"><A NAME="Heading29"></A><FONT COLOR="#000077">Exercises</FONT></H4>

<DL>
	<DD><B>1</B>. Write a program that declares an <TT>int</TT>, a reference to an <TT>int</TT>,
	and a pointer to an <TT>int</TT>. Use the pointer and the reference to manipulate
	the value in the <TT>int</TT>.
</DL>

<PRE><FONT COLOR="#0066FF">int main()
{
int varOne;
int&amp; rVar = varOne;
int* pVar = &amp;varOne;
rVar = 5;
*pVar = 7;
return 0;
}
</FONT></PRE>

<DL>
	<DD><B>2.</B> Write a program that declares a constant pointer to a constant integer.
	Initialize the pointer to an integer variable, <TT>varOne</TT>. Assign <TT>6</TT>
	to <TT>varOne</TT>. Use the pointer to assign <TT>7</TT> to <TT>varOne</TT>. Create
	a second integer variable, <TT>varTwo</TT>. Reassign the pointer to <TT>varTwo</TT>.
</DL>

<PRE><FONT COLOR="#0066FF">int main()
{
   int varOne;
   const int * const pVar = &amp;varOne;
   *pVar = 7;
   int varTwo;
   pVar = &amp;varTwo;
return 0;
}
</FONT></PRE>

<DL>
	<DD><B>3.</B> Compile the program in Exercise 2. What produces errors? What produces
	warnings?<BR>
	You can't assign a value to a constant object, and you can't reassign a constant
	pointer.<BR>
	<BR>
	<B>4.</B> Write a program that produces a stray pointer.
</DL>

<PRE><FONT COLOR="#0066FF">int main()
{
int * pVar;
*pVar = 9;
return 0;
}
</FONT></PRE>

<DL>
	<DD><B>5.</B> Fix the program from Exercise 4.
</DL>

<PRE><FONT COLOR="#0066FF">int main()
{
int VarOne;
int * pVar = &amp;varOne;
*pVar = 9;
return 0;
}
</FONT></PRE>

<DL>
	<DD><B>6.</B> Write a program that produces a memory leak.
</DL>

<PRE><FONT COLOR="#0066FF">int FuncOne();
int main()
{
   int localVar = FunOne();
   cout &lt;&lt; &quot;the value of localVar is: &quot; &lt;&lt; localVar;
return 0;
}

int FuncOne()
{
   int * pVar = new int (5);
   return *pVar;
}
</FONT></PRE>

<DL>
	<DD><B>7.</B> Fix the program from Exercise 6.
</DL>

<PRE><FONT COLOR="#0066FF">void FuncOne();
int main()
{
   FuncOne();
return 0;
}

void FuncOne()
{
   int * pVar = new int (5);
   cout &lt;&lt; &quot;the value of *pVar is: &quot; &lt;&lt; *pVar ;
}
</FONT></PRE>

<DL>
	<DD><B>8.</B> BUG BUSTERS: What is wrong with this program?
</DL>

<PRE><FONT COLOR="#0066FF">1:     #include &lt;iostream.h&gt;
2:
3:     class CAT
4:     {
5:        public:
6:           CAT(int age) { itsAge = age; }
7:           ~CAT(){}
8:           int GetAge() const { return itsAge;}
9:        private:
10:          int itsAge;
11:    };
12:
13:    CAT &amp; MakeCat(int age);
14:    int main()
15:    {
16:       int age = 7;
17:       CAT Boots = MakeCat(age);
18:       cout &lt;&lt; &quot;Boots is &quot; &lt;&lt; Boots.GetAge() &lt;&lt; &quot; years old\n&quot;;
19:     return 0;
20:    }
21:
22:    CAT &amp; MakeCat(int age)
23:    {
24:       CAT * pCat = new CAT(age);
25:       return *pCat;
26:    }
</FONT></PRE>

<DL>
	<DD><TT>MakeCat</TT> returns a reference to the <TT>CAT</TT> created on the free
	store. There is no way to free that memory, and this produces a memory leak.<BR>
	<BR>
	<B>9.</B> Fix the program from Exercise 8.
</DL>

<PRE><FONT COLOR="#0066FF">1:     #include &lt;iostream.h&gt;
2:
3:     class CAT
4:     {
5:        public:
6:           CAT(int age) { itsAge = age; }
7:           ~CAT(){}
8:           int GetAge() const { return itsAge;}
9:        private:
10:          int itsAge;
11:    };
12:
13:    CAT * MakeCat(int age);
14:    int main()
15:    {
16:       int age = 7;
17:       CAT * Boots = MakeCat(age);
18:       cout &lt;&lt; &quot;Boots is &quot; &lt;&lt; Boots-&gt;GetAge() &lt;&lt; &quot; years old\n&quot;;
19:       delete Boots;
20:     return 0;
21:    }
22:
23:    CAT * MakeCat(int age)
24:    {
25:       return new CAT(age);
26:    }
</FONT></PRE>
<H3 ALIGN="CENTER"><FONT COLOR="#0066FF"></FONT></H3>
<H3><A NAME="Heading30"></A><FONT COLOR="#000077">Day 10</FONT></H3>
<H4 ALIGN="CENTER"><A NAME="Heading31"></A><FONT COLOR="#000077">Quiz</FONT></H4>

<DL>
	<DD><B>1. When you overload member functions, in what ways must they differ?<BR>
	</B><BR>
	Overloaded member functions are functions in a class that share a name but differ
	in the number or type of their parameters.<BR>