Grep for character with uppercase and number

Hello,

I would like to be able to extract the uppercase character or the uppercase character which has a number, here is my grep which works for the uppercase characters, but I cannot manage to capture the uppercase character and having number, I tried

grep " [A-Z]\\+" -x text.txt

text.txt:

#############
between
for
TAR
torsions:
##########

The Answer : TAR
It’s ok.
But,

grep " [A-Z]\\+" -x 
grep " [0-9]\\+" -x 
grep "[A-Z]\\+ |[0-9]" -x 
grep "[A-Z]\\+ |[^0-9]{1} " -x

txt2.txt:

###########
between
for
P1A
torsions:
###########

Don’t capture P1A, I don’t want to do the : grep “P1A” , because I have several files to process in series, with the same problem

Best,

Try this one:

grep "[[:upper:]][[:digit:]]" input.txt