Why the if statement cannot function properly in cpp

I double-checked my if-statement, they should be working, but I got this error and couldn't solve it. Appreciate your help, thx!

PS C:\Users\XXX\Desktop\test C++> cd "c:\Users\XXX\Desktop\test C++\" ; if ($?) { g++ if 
sentence.cpp -o if sentence } ; if ($?) { .\if sentence }
g++.exe: error: if: No such file or directory
g++.exe: error: sentence.cpp: No such file or directory
g++.exe: error: sentence: No such file or directory
g++.exe: fatal error: no input files

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