Apple Mach-O链接器（id）错误 我试图在XCOD.< /P>上编译一个C++项目

我犯了这个错误，我真的不知道该怎么办

搜索了类似的问题，但没有任何帮助

以下是错误：

Ld /Users/itzikhanoch/Library/Developer/Xcode/DerivedData/ex4-eepdugqcjenwebctvbtmtbkyguxu/Build/Products/Debug/ex4 normal x86_64
cd /Users/itzikhanoch/Documents/XcodeWorkspace/ex4
setenv MACOSX_DEPLOYMENT_TARGET 10.7
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang++ -arch x86_64 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.7.sdk -L/Users/itzikhanoch/Library/Developer/Xcode/DerivedData/ex4-eepdugqcjenwebctvbtmtbkyguxu/Build/Products/Debug -F/Users/itzikhanoch/Library/Developer/Xcode/DerivedData/ex4-eepdugqcjenwebctvbtmtbkyguxu/Build/Products/Debug -filelist /Users/itzikhanoch/Library/Developer/Xcode/DerivedData/ex4-eepdugqcjenwebctvbtmtbkyguxu/Build/Intermediates/ex4.build/Debug/ex4.build/Objects-normal/x86_64/ex4.LinkFileList -mmacosx-version-min=10.7 -o /Users/itzikhanoch/Library/Developer/Xcode/DerivedData/ex4-eepdugqcjenwebctvbtmtbkyguxu/Build/Products/Debug/ex4

Undefined symbols for architecture x86_64:
"_main", referenced from:
  start in crt1.10.6.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

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<> P>所有的C++和C++代码都必须有一个全局的<代码>主< /代码>函数，在那里执行开始。根据规范，

main

函数还必须返回一个整数，并且没有或有两个特定参数：

int main()

int main(int, char **)

int main(int, char *[])

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您确实有一个全局

main

函数吗？如果您正在构建应用程序，则需要一个main，但如果您正在构建库，则不需要。