Question

我只是通过udemy课程学习了指针，但是偶然发现了这个问题。我尝试使用以下代码显示变量num的地址：

#include <iostream>

using namespace std;

int main()
{
    int qon = 200;
    int *num = &qon;
    cout << "Content of num is " << *num << endl;
    cout << "The location of num is " << (unsigned) num << end;
    cout << "The size of num is " << sizeof(num) << endl;
    return 0;
}

这是错误消息：

||=== Build: Debug in Pointers tutorial (compiler: GNU GCC Compiler) ===|
D:\1. Kuliah\Semester 1\Elements of Programming - CSC 1100\Self Study\Assignment\Pointers tutorial\main.cpp||In function 'int main()':|
D:\1. Kuliah\Semester 1\Elements of Programming - CSC 1100\Self Study\Assignment\Pointers tutorial\main.cpp|10|error: no match for 'operator<<' (operand types are 'std::basic_ostream<char>::__ostream_type {aka std::basic_ostream<char>}' and '<unresolved overloaded function type>')|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\ostream|108|note: candidate: std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(std::basic_ostream<_CharT, _Traits>::__ostream_type& (*)(std::basic_ostream<_CharT, _Traits>::__ostream_type&)) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_ostream<_CharT, _Traits>::__ostream_type = std::basic_ostream<char>]|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\ostream|108|note:   no known conversion for argument 1 from '<unresolved overloaded function type>' to 'std::basic_ostream<char>::__ostream_type& (*)(std::basic_ostream<char>::__ostream_type&) {aka std::basic_ostream<char>& (*)(std::basic_ostream<char>&)}'|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\ostream|117|note: candidate: std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(std::basic_ostream<_CharT, _Traits>::__ios_type& (*)(std::basic_ostream<_CharT, _Traits>::__ios_type&)) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_ostream<_CharT, _Traits>::__ostream_type = std::basic_ostream<char>; std::basic_ostream<_CharT, _Traits>::__ios_type = std::basic_ios<char>]|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\ostream|117|note:   no known conversion for argument 1 from '<unresolved overloaded function type>' to 'std::basic_ostream<char>::__ios_type& (*)(std::basic_ostream<char>::__ios_type&) {aka std::basic_ios<char>& (*)(std::basic_ios<char>&)}'|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\ostream|127|note: candidate: std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(std::ios_base& (*)(std::ios_base&)) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_ostream<_CharT, _Traits>::__ostream_type = std::basic_ostream<char>]|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\ostream|127|note:   no known conversion for argument 1 from '<unresolved overloaded function type>' to 'std::ios_base& (*)(std::ios_base&)'|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\ostream|166|note: candidate: std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(long int) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_ostream<_CharT, _Traits>::__ostream_type = std::basic_ostream<char>]|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\ostream|166|note:   no known conversion for argument 1 from '<unresolved overloaded function type>' to 'long int'|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\ostream|170|note: candidate: std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(long unsigned int) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_ostream<_CharT, _Traits>::__ostream_type = std::basic_ostream<char>]|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\ostream|170|note:   no known conversion for argument 1 from '<unresolved overloaded function type>' to 'long unsigned int'|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\ostream|174|note: candidate: std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(bool) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_ostream<_CharT, _Traits>::__ostream_type = std::basic_ostream<char>]|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\ostream|174|note:   no known conversion for argument 1 from '<unresolved overloaded function type>' to 'bool'|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\bits\ostream.tcc|91|note: candidate: std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(short int) [with _CharT = char; _Traits = std::char_traits<char>]|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\bits\ostream.tcc|91|note:   no known conversion for argument 1 from '<unresolved overloaded function type>' to 'short int'|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\ostream|181|note: candidate: std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(short unsigned int) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_ostream<_CharT, _Traits>::__ostream_type = std::basic_ostream<char>]|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\ostream|181|note:   no known conversion for argument 1 from '<unresolved overloaded function type>' to 'short unsigned int'|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\bits\ostream.tcc|105|note: candidate: std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(int) [with _CharT = char; _Traits = std::char_traits<char>]|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\bits\ostream.tcc|105|note:   no known conversion for argument 1 from '<unresolved overloaded function type>' to 'int'|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\ostream|192|note: candidate: std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(unsigned int) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_ostream<_CharT, _Traits>::__ostream_type = std::basic_ostream<char>]|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\ostream|192|note:   no known conversion for argument 1 from '<unresolved overloaded function type>' to 'unsigned int'|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\ostream|201|note: candidate: std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(long long int) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_ostream<_CharT, _Traits>::__ostream_type = std::basic_ostream<char>]|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\ostream|201|note:   no known conversion for argument 1 from '<unresolved overloaded function type>' to 'long long int'|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\ostream|205|note: candidate: std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(long long unsigned int) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_ostream<_CharT, _Traits>::__ostream_type = std::basic_ostream<char>]|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\ostream|205|note:   no known conversion for argument 1 from '<unresolved overloaded function type>' to 'long long unsigned int'|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\ostream|220|note: candidate: std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(double) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_ostream<_CharT, _Traits>::__ostream_type = std::basic_ostream<char>]|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\ostream|220|note:   no known conversion for argument 1 from '<unresolved overloaded function type>' to 'double'|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\ostream|224|note: candidate: std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(float) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_ostream<_CharT, _Traits>::__ostream_type = std::basic_ostream<char>]|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\ostream|224|note:   no known conversion for argument 1 from '<unresolved overloaded function type>' to 'float'|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\ostream|232|note: candidate: std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(long double) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_ostream<_CharT, _Traits>::__ostream_type = std::basic_ostream<char>]|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\ostream|232|note:   no known conversion for argument 1 from '<unresolved overloaded function type>' to 'long double'|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\ostream|245|note: candidate: std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(const void*) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_ostream<_CharT, _Traits>::__ostream_type = std::basic_ostream<char>]|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\ostream|245|note:   no known conversion for argument 1 from '<unresolved overloaded function type>' to 'const void*'|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\bits\ostream.tcc|119|note: candidate: std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(std::basic_ostream<_CharT, _Traits>::__streambuf_type*) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_ostream<_CharT, _Traits>::__streambuf_type = std::basic_streambuf<char>]|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\bits\ostream.tcc|119|note:   no known conversion for argument 1 from '<unresolved overloaded function type>' to 'std::basic_ostream<char>::__streambuf_type* {aka std::basic_streambuf<char>*}'|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\bits\basic_string.h|5167|note: candidate: template<class _CharT, class _Traits, class _Alloc> std::basic_ostream<_CharT, _Traits>& std::operator<<(std::basic_ostream<_CharT, _Traits>&, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\bits\basic_string.h|5167|note:   template argument deduction/substitution failed:|
D:\1. Kuliah\Semester 1\Elements of Programming - CSC 1100\Self Study\Assignment\Pointers tutorial\main.cpp|10|note:   couldn't deduce template parameter '_Alloc'|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\system_error|209|note: candidate: template<class _CharT, class _Traits> std::basic_ostream<_CharT, _Traits>& std::operator<<(std::basic_ostream<_CharT, _Traits>&, const std::error_code&)|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\system_error|209|note:   template argument deduction/substitution failed:|
D:\1. Kuliah\Semester 1\Elements of Programming - CSC 1100\Self Study\Assignment\Pointers tutorial\main.cpp|10|note:   cannot convert 'std::end' (type '<unresolved overloaded function type>') to type 'const std::error_code&'|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\ostream|497|note: candidate: std::basic_ostream<_CharT, _Traits>& std::operator<<(std::basic_ostream<_CharT, _Traits>&, _CharT) [with _CharT = char; _Traits = std::char_traits<char>]|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\ostream|497|note:   no known conversion for argument 2 from '<unresolved overloaded function type>' to 'char'|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\ostream|502|note: candidate: template<class _CharT, class _Traits> std::basic_ostream<_CharT, _Traits>& std::operator<<(std::basic_ostream<_CharT, _Traits>&, char)|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\ostream|502|note:   template argument deduction/substitution failed:|
D:\1. Kuliah\Semester 1\Elements of Programming - CSC 1100\Self Study\Assignment\Pointers tutorial\main.cpp|10|note:   cannot convert 'std::end' (type '<unresolved overloaded function type>') to type 'char'|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\ostream|508|note: candidate: template<class _Traits> std::basic_ostream<char, _Traits>& std::operator<<(std::basic_ostream<char, _Traits>&, char)|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\ostream|508|note:   template argument deduction/substitution failed:|
D:\1. Kuliah\Semester 1\Elements of Programming - CSC 1100\Self Study\Assignment\Pointers tutorial\main.cpp|10|note:   cannot convert 'std::end' (type '<unresolved overloaded function type>') to type 'char'|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\ostream|514|note: candidate: template<class _Traits> std::basic_ostream<char, _Traits>& std::operator<<(std::basic_ostream<char, _Traits>&, signed char)|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\ostream|514|note:   template argument deduction/substitution failed:|
D:\1. Kuliah\Semester 1\Elements of Programming - CSC 1100\Self Study\Assignment\Pointers tutorial\main.cpp|10|note:   cannot convert 'std::end' (type '<unresolved overloaded function type>') to type 'signed char'|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\ostream|519|note: candidate: template<class _Traits> std::basic_ostream<char, _Traits>& std::operator<<(std::basic_ostream<char, _Traits>&, unsigned char)|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\ostream|519|note:   template argument deduction/substitution failed:|
D:\1. Kuliah\Semester 1\Elements of Programming - CSC 1100\Self Study\Assignment\Pointers tutorial\main.cpp|10|note:   cannot convert 'std::end' (type '<unresolved overloaded function type>') to type 'unsigned char'|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\ostream|539|note: candidate: std::basic_ostream<_CharT, _Traits>& std::operator<<(std::basic_ostream<_CharT, _Traits>&, const _CharT*) [with _CharT = char; _Traits = std::char_traits<char>]|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\ostream|539|note:   no known conversion for argument 2 from '<unresolved overloaded function type>' to 'const char*'|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\bits\ostream.tcc|321|note: candidate: template<class _CharT, class _Traits> std::basic_ostream<_CharT, _Traits>& std::operator<<(std::basic_ostream<_CharT, _Traits>&, const char*)|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\bits\ostream.tcc|321|note:   template argument deduction/substitution failed:|
D:\1. Kuliah\Semester 1\Elements of Programming - CSC 1100\Self Study\Assignment\Pointers tutorial\main.cpp|10|note:   cannot convert 'std::end' (type '<unresolved overloaded function type>') to type 'const char*'|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\ostream|556|note: candidate: template<class _Traits> std::basic_ostream<char, _Traits>& std::operator<<(std::basic_ostream<char, _Traits>&, const char*)|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\ostream|556|note:   template argument deduction/substitution failed:|
D:\1. Kuliah\Semester 1\Elements of Programming - CSC 1100\Self Study\Assignment\Pointers tutorial\main.cpp|10|note:   cannot convert 'std::end' (type '<unresolved overloaded function type>') to type 'const char*'|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\ostream|569|note: candidate: template<class _Traits> std::basic_ostream<char, _Traits>& std::operator<<(std::basic_ostream<char, _Traits>&, const signed char*)|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\ostream|569|note:   template argument deduction/substitution failed:|
D:\1. Kuliah\Semester 1\Elements of Programming - CSC 1100\Self Study\Assignment\Pointers tutorial\main.cpp|10|note:   cannot convert 'std::end' (type '<unresolved overloaded function type>') to type 'const signed char*'|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\ostream|574|note: candidate: template<class _Traits> std::basic_ostream<char, _Traits>& std::operator<<(std::basic_ostream<char, _Traits>&, const unsigned char*)|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\ostream|574|note:   template argument deduction/substitution failed:|
D:\1. Kuliah\Semester 1\Elements of Programming - CSC 1100\Self Study\Assignment\Pointers tutorial\main.cpp|10|note:   cannot convert 'std::end' (type '<unresolved overloaded function type>') to type 'const unsigned char*'|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\ostream|628|note: candidate: template<class _CharT, class _Traits, class _Tp> std::basic_ostream<_CharT, _Traits>& std::operator<<(std::basic_ostream<_CharT, _Traits>&&, const _Tp&)|
C:\Program Files (x86)\CodeBlocks\MinGW\lib\gcc\mingw32\5.1.0\include\c++\ostream|628|note:   template argument deduction/substitution failed:|
D:\1. Kuliah\Semester 1\Elements of Programming - CSC 1100\Self Study\Assignment\Pointers tutorial\main.cpp|10|note:   couldn't deduce template parameter '_Tp'|
||=== Build failed: 1 error(s), 0 warning(s) (0 minute(s), 0 second(s)) ===|

Answer 1

有错字

cout << "The location of num is " << (unsigned) num << end;
                                                       ^^^^

你是说

cout << "The location of num is " << (unsigned) num << endl;
                                                       ^^^^

并使用

cout << "The location of num is " << (void *) num << endl;

或

cout << "The location of num is " << static_cast<void *>( num ) << endl;

或者只是

cout << "The location of num is " << num << endl;

为什么我不能显示指针的地址？

1 个答案: