I have a problem doing the following process in bash script:

f=0
for ((i=0; i<=1000; i++)) {
  # do something
  if [ diff -w out_1 out_2 ]
  then
    f=1
    break
  fi
}

I mean, if the diff command gave anything as an output(the files were different), break the loop and set the variable f to 1
but this gives error and I couldn’t find any way to do it