C/C ++ questions (from Zhou xing's blog)

Haha, I don't know if it is helpful for some pen/interview :)
1. What are output by the following three output statements? [C ease]
Char str1 [] = "ABC ";
Char str2 [] = "ABC ";
Const char str3 [] = "ABC ";
Const char str4 [] = "ABC ";
Const char * str5 = "ABC ";
Const char * str6 = "ABC ";
Cout <boolalpha <(str1 = str2) <Endl; // What is output?
Cout <boolalpha <(str3 = str4) <Endl; // What is output?
Cout <boolalpha <(str5 = str6) <Endl; // What is output?

2. Where can B be implicitly converted to a for non-C ++ built-in types A and B? [C ++ medium]
A:
A. Class B: Public {......} // The Public B inherits from a and can be indirectly inherited.
B. Class B {operator A ();} // B implements implicit conversion to
C. Class A {A (const B &) ;}// a constructor that implements the non-explicit parameter as B (other parameters with default values can be available)
D. A & operator = (const A &); // value assignment operation. Although it is not an authentic implicit type conversion operation, it can barely calculate

3. The followingCodeIs there a problem with the usage of the two sizeof in? [C ease]
Void uppercase (char STR []) // converts lowercase letters in STR to uppercase letters.
{
For (size_t I = 0; I & ltsizeof (STR)/sizeof (STR [0]); ++ I)
If ('A' <= STR [I] & STR [I] <= 'Z ')
STR [I]-= ('A'-'A ');
}
Char STR [] = "ABCDE ";
Cout <"str character length:" <sizeof (STR)/sizeof (STR [0]) <Endl;
Uppercase (STR );
Cout <STR <Endl;

4. What is the problem with the following code? [C hard]
Void char2hex (char c) // represents the character in hexadecimal notation
{
Char CH = C/0x10 + '0'; If (CH> '9') CH + = ('A'-'9'-1 );
Char Cl = C % 0x10 + '0'; If (Cl> '9') Cl + = ('A'-'9'-1 );
Cout <ch <CL <'';
}
Char STR [] = "I love China ";
For (size_t I = 0; I & ltstrlen (STR); ++ I)
Char2hex (STR [I]);
Cout <Endl;

5. What is the problem with the following code? [C ++ ease]
Struct Test
{
Test (INT ){}
Test (){}
Void fun (){}
};
Void main (void)
{
Test A (1 );
A. Fun ();
Test B ();
B. Fun ();
}

6. What is the problem with the following code? [C ++ ease]
Cout <(true? 1: "1") <Endl;

7. Can the following code be compiled? Why? [C ++ ease]
Unsigned int const size1 = 2;
Char str1 [size1];
Unsigned int temp = 0;
Cin> temp;
Unsigned int const size2 = temp;
Char str2 [size2];

8. Is the output statement in the following code 0? Why? [C ++ ease]
Struct CLS
{
Int m_ I;
CLS (int I): m_ I (I ){}
CLS ()
{
CLS (0 );
}
};
Cls obj;
Cout <obj. m_ I <Endl;

9. Which class member functions are generated by default for empty classes in C ++? [C ++ ease]
answer:
class empty
{< br> Public:
Empty (); // default constructor
Empty (const empty &); // copy the constructor
~ Empty (); // destructor
Empty & operator = (const empty &); // value assignment operator
empty * operator &(); // address retrieval operator
const empty * operator & () const; // address retrieval operator const
};

10. What are the outputs of the following two output statements? [C ++ difficulties]
Float a = 1.0f;
Cout <(INT) A <Endl;
Cout <(Int &) A <Endl;
Cout <boolalpha <(INT) A = (Int &) a) <Endl; // What is output?
Float B = 0.0f;
Cout <(INT) B <Endl;
Cout <(Int &) B <Endl;
Cout <boolalpha <(INT) B = (Int &) B) <Endl; // What is output?

11. What are the following error methods for reverse traversing array? [STL ease]
Vector Array;
Array. push_back (1 );
Array. push_back (2 );
Array. push_back (3 );
For (vector: size_type I = array. Size ()-1; I> = 0; -- I) // reverse traversal of the array
{
Cout <array [I] <Endl;
}

12. What is the problem with the following code? [STL ease]
Typedef Vector Intarray;
Intarray array;
Array. push_back (1 );
Array. push_back (2 );
Array. push_back (2 );
Array. push_back (3 );
// Delete all 2 in the array
For (intarray: iterator itor = array. Begin (); itor! = Array. End (); ++ itor)
{
If (2 = * itor) array. Erase (itor );
}

13. Write a function to copy data between memories. [Whether the problem is comprehensive]
A:
Void * mymemcpy (void * DEST, const void * SRC, size_t count)
{
Char * pdest = static_cast & ltchar *> (DEST );
Const char * psrc = static_cast & ltconst char *> (SRC );
If (pdest> psrc & pdest & ltpsrc + cout) can take this situation into consideration.
{
For (size_t I = count-1; I! =-1; -- I)
Pdest [I] = psrc [I];
}
Else
{
For (size_t I = 0; I & ltcount; ++ I)
Pdest [I] = psrc [I];
}
Return DEST;
}
Int main (void)
{
Char STR [] = "0123456789 ";
Mymemcpy (STR + 1, STR + 0, 9 );
Cout <STR <Endl;

System ("pause ");
Return 0;
}