$\_ENV ：存储了一些系统的环境变量 **打印$\_ENV为空的可能原因：** php.ini的variables\_order值为"GPCS" 你可以修改php.ini文件的 variables\_order值为你想要的顺序，如："EGPCS" EGPCS是Environment、Get、Post、Cookies、Server的缩写 ~~~ Array ( [ALLUSERSPROFILE] => C:\ProgramData [APPDATA] => C:\Users\Administrator\AppData\Roaming [CommonProgramFiles] => C:\Program Files (x86)\Common Files [CommonProgramFiles(x86)] => C:\Program Files (x86)\Common Files [CommonProgramW6432] => C:\Program Files\Common Files [COMPUTERNAME] => USER-20160524DB [ComSpec] => C:\Windows\system32\cmd.exe [FP_NO_HOST_CHECK] => NO [HOMEDRIVE] => C: [HOMEPATH] => \Users\Administrator [LOCALAPPDATA] => C:\Users\Administrator\AppData\Local [LOGONSERVER] => \\USER-20160524DB [MOZ_PLUGIN_PATH] => D:\Haihaisoft PDF Reader\ [NUMBER_OF_PROCESSORS] => 4 [OS] => Windows_NT [Path] => C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;D:\xampp\php;C:\ProgramData\ComposerSetup\bin;D:\xampp\php;d:\Program Files\Git\cmd;d:\xampp\mysql\bin;C:\Users\Administrator\AppData\Roaming\Composer\vendor\bin;C:\ProgramData\ComposerSetup\bin;C:\Users\Administrator\AppData\Local\GitHubDesktop\bin [PATHEXT] => .COM;.EXE;.BAT;.CMD;.VBS;.VBE;.JS;.JSE;.WSF;.WSH;.MSC [PROCESSOR_ARCHITECTURE] => x86 [PROCESSOR_ARCHITEW6432] => AMD64 [PROCESSOR_IDENTIFIER] => Intel64 Family 6 Model 23 Stepping 10, GenuineIntel [PROCESSOR_LEVEL] => 6 [PROCESSOR_REVISION] => 170a [ProgramData] => C:\ProgramData [ProgramFiles] => C:\Program Files (x86) [ProgramFiles(x86)] => C:\Program Files (x86) [ProgramW6432] => C:\Program Files [PSModulePath] => C:\Windows\system32\WindowsPowerShell\v1.0\Modules\ [PUBLIC] => C:\Users\Public [SESSIONNAME] => Console [SystemDrive] => C: [SystemRoot] => C:\Windows [TEMP] => C:\Users\ADMINI~1\AppData\Local\Temp [TMP] => C:\Users\ADMINI~1\AppData\Local\Temp [USERDOMAIN] => USER-20160524DB [USERNAME] => Administrator [USERPROFILE] => C:\Users\Administrator [windir] => C:\Windows [windows_tracing_flags] => 3 [windows_tracing_logfile] => C:\BVTBin\Tests\installpackage\csilogfile.log [_DFX_INSTALL_UNSIGNED_DRIVER] => 1 [AP_PARENT_PID] => 5692 ) ~~~