number of tokens in bash variable

Question

how can I know the number of tokens in a bash variable (whitespace-separated tokens) - or at least, wether it is one or there are more.

Answer 1

To count:

sentence="This is a sentence, please count the words in me."
words="${sentence//[^\ ]} "
echo ${#words}

To check:

sentence1="Two words"
sentence2="One"
[[ "$sentence1" =~ [\ ] ]] && echo "sentence1 has more than one word"
[[ "$sentence2" =~ [\ ] ]] && echo "sentence2 has more than one word"