Why R cannot read a csv file in a working directory?

[R-Master]

I tried to load a CSV file but failed.
so this time, I created a file with R in the working directory and tried to read it but also failed.
Please let me know the reason.
Thank you so much in advance.

AAA
x y z
1 1 a T
2 2 b F
3 3 c T
write.csv(AAA,file = "AAA.csv",row.names = FALSE)
read.csv("AAA",header = TRUE)
Error in file(file, "rt") : cannot open the connection
In addition: Warning message:
In file(file, "rt") : cannot open file 'AAA': No such file or directory

[jlacko]

Are you sure you have got the file names right? You seem to be missing the extension in your read.csv() call...

@R-Master

write.csv(AAA,file = "AAA.csv",row.names = FALSE)
read.csv("AAA",header = TRUE)

You may want to consider read.csv("AAA.csv") instead.

[R-Master]

Thank you so much.
Sometimes stupid trivial errors annoy me and make me waste a long time.