C++学习

系列文章目录

第一章 C++编译与链接

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前言

C++编译基础、头文件、以及基础数据类型

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1.cpp与hpp

main.cpp包含函数主体内容，
main.hpp包含一些函数声明，
function.cpp可以包含一些定义的函数主体，将函数声明放在.hpp中

2.头文件

通过引用头文件，实现调用头文件包含的函数，
#include
#include"main.hpp"
通过引入“iostream”,可以调用"std::cout"实现cout函数的调用
通过编译命名空间std
using namespace std
可以直接使用cout

#include<iostream>
using namespace std;
int main()
{
	cout<<"hello Word"<<endl;
	return 0;
}

endl等价于"\n"

该代码等价于

#include<iostream>
using namespace std;
int main()
{
	cout<<"hello Word\n";
	return 0;
}

3.g++编译代码

采用g++进行代码编译

g++ ./main.cpp   -o ./main

-o指定输出文件名

root@4b2011dc6b43:/data/CPP/week02/examples# g++ --help
Usage: g++ [options] file...
Options:
  -pass-exit-codes         Exit with highest error code from a phase.
  --help                   Display this information.
  --target-help            Display target specific command line options.
  --help={common|optimizers|params|target|warnings|[^]{joined|separate|undocumented}}[,...].
                           Display specific types of command line options.
  (Use '-v --help' to display command line options of sub-processes).
  --version                Display compiler version information.
  -dumpspecs               Display all of the built in spec strings.
  -dumpversion             Display the version of the compiler.
  -dumpmachine             Display the compiler's target processor.
  -print-search-dirs       Display the directories in the compiler's search path.
  -print-libgcc-file-name  Display the name of the compiler's companion library.
  -print-file-name=<lib>   Display the full path to library <lib>.
  -print-prog-name=<prog>  Display the full path to compiler component <prog>.
  -print-multiarch         Display the target's normalized GNU triplet, used as
                           a component in the library path.
  -print-multi-directory   Display the root directory for versions of libgcc.
  -print-multi-lib         Display the mapping between command line options and
                           multiple library search directories.
  -print-multi-os-directory Display the relative path to OS libraries.
  -print-sysroot           Display the target libraries directory.
  -print-sysroot-headers-suffix Display the sysroot suffix used to find headers.
  -Wa,<options>            Pass comma-separated <options> on to the assembler.
  -Wp,<options>            Pass comma-separated <options> on to the preprocessor.
  -Wl,<options>            Pass comma-separated <options> on to the linker.
  -Xassembler <arg>        Pass <arg> on to the assembler.
  -Xpreprocessor <arg>     Pass <arg> on to the preprocessor.
  -Xlinker <arg>           Pass <arg> on to the linker.
  -save-temps              Do not delete intermediate files.
  -save-temps=<arg>        Do not delete intermediate files.
  -no-canonical-prefixes   Do not canonicalize paths when building relative
                           prefixes to other gcc components.
  -pipe                    Use pipes rather than intermediate files.
  -time                    Time the execution of each subprocess.
  -specs=<file>            Override built-in specs with the contents of <file>.
  -std=<standard>          Assume that the input sources are for <standard>.
  --sysroot=<directory>    Use <directory> as the root directory for headers
                           and libraries.
  -B <directory>           Add <directory> to the compiler's search paths.
  -v                       Display the programs invoked by the compiler.
  -###                     Like -v but options quoted and commands not executed.
  -E                       Preprocess only; do not compile, assemble or link.
  -S                       Compile only; do not assemble or link.
  -c                       Compile and assemble, but do not link.
  -o <file>                Place the output into <file>.
  -pie                     Create a dynamically linked position independent
                           executable.
  -shared                  Create a shared library.
  -x <language>            Specify the language of the following input files.
                           Permissible languages include: c c++ assembler none
                           'none' means revert to the default behavior of
                           guessing the language based on the file's extension.

Options starting with -g, -f, -m, -O, -W, or --param are automatically
 passed on to the various sub-processes invoked by g++.  In order to pass
 other options on to these processes the -W<letter> options must be used.

For bug reporting instructions, please see:
<file:///usr/share/doc/gcc-9/README.Bugs>.

4.常见问题

注意代码采用的是哪种类型的c++标准
常见的编译错误{主要是语法错误}
常见的连接错误{函数调用错误，如函数名定义错误}
运行错误交难排查：数值运算、内存问题
C++支持调用C语言的大多数函数