Evaluating XPath Expresssions

XPath Result of XPath Evaluation
count(tokenize('bab', 'ab|a'))
2
tokenize('bab', 'ab|a')[1]
'b'
tokenize('bab', 'ab|a')[2]
''
count(tokenize('bab', 'ab?'))
2
tokenize('bab', 'ab?')[1]
'b'
tokenize('bab', 'ab?')[2]
''