The HasVowel(s) command tests whether any character in its argument s is an English language vowel.

The vowels are, by definition, the ten characters $''a''$, $''e''$, $''i''$, $''o''$, $''u''$, $''A''$, $''E''$, $''I''$, $''O''$ and $''U''$. No other character is a vowel. In particular, the characters $''y''$ and $''Y''$ are not considered to be vowels for this test.

If any character of the string s is a vowel character, then the value true is returned. Otherwise, the value false is returned.

All of the StringTools package commands treat strings as (null-terminated) sequences of $8$-bit (ASCII) characters.  Thus, there is no support for multibyte character encodings, such as unicode encodings.

The StringTools[HasVowel] command is thread-safe as of Maple 15.

For more information on thread safety, see index/threadsafe.

$\mathrm{with}\left(\mathrm{StringTools}\right)\:$

$\mathrm{HasVowel}\left(''foobar''\right)$

$\mathrm{true}$

$\mathrm{HasVowel}\left(''dfghjkl''\right)$

$\mathrm{false}$