LetterQ

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`LetterQ`

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LetterQ[string]

yields True if all the characters in the string are letters, and yields False otherwise.

Details

LetterQ[string] by default gives False if string contains any space or punctuation characters.
LetterQ handles both ordinary and special characters.
LetterQ treats as letters all special characters explicitly listed as letters in the table in "Named Characters".
In general, LetterQ treats as letters all characters that appear as ordinary text in any language.
LetterQ treats as letters such special characters as α, , ℒ, and æ.
LetterQ does not treat as letters ∅ (\[EmptySet]), ℏ (\[HBar]), Å (\[Angstrom]), or ∑ (\[Sum]).

Examples

open allclose all

Basic Examples (1)Summary of the most common use cases

Test whether a character is a letter:

In[1]:=1

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https://wolfram.com/xid/0tz3ek27-p3d

Out[1]=1

In[2]:=2

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https://wolfram.com/xid/0tz3ek27-irl

Out[2]=2

Scope (6)Survey of the scope of standard use cases

Test whether all characters in a string are letters:

In[1]:=1

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https://wolfram.com/xid/0tz3ek27-shd

Out[1]=1

Punctuation is not a letter:

In[1]:=1

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https://wolfram.com/xid/0tz3ek27-gaf

Out[1]=1

Accented letters are still treated as letters:

In[1]:=1

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https://wolfram.com/xid/0tz3ek27-v1y

Out[1]=1

Gothic letters are treated as letters:

In[1]:=1

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https://wolfram.com/xid/0tz3ek27-l5j

Out[1]=1

Greek letters are treated as letters:

In[1]:=1

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https://wolfram.com/xid/0tz3ek27-pyv

Out[1]=1

Characters that are not letters in ordinary natural language are not treated as letters:

In[1]:=1

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https://wolfram.com/xid/0tz3ek27-vfl

Out[1]=1

In[2]:=2

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https://wolfram.com/xid/0tz3ek27-t8u

Out[2]=2

Generalizations & Extensions (1)Generalized and extended use cases

Letters from different character ranges corresponding to different languages:

In[1]:=1

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https://wolfram.com/xid/0tz3ek27-forngn

Out[1]=1

In[2]:=2

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https://wolfram.com/xid/0tz3ek27-ejmbpx

Out[2]=2

In[3]:=3

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https://wolfram.com/xid/0tz3ek27-bpzm5e

Out[3]=3

In[4]:=4

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https://wolfram.com/xid/0tz3ek27-c04vzr

Out[4]=4

In[5]:=5

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https://wolfram.com/xid/0tz3ek27-f6eoji

Out[5]=5

In[6]:=6

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https://wolfram.com/xid/0tz3ek27-h08k5h

Out[6]=6

In[7]:=7

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https://wolfram.com/xid/0tz3ek27-fcttyv

Out[7]=7

Properties & Relations (1)Properties of the function, and connections to other functions

All characters treated as letters:

In[1]:=1

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https://wolfram.com/xid/0tz3ek27-of3

Out[1]=1

Possible Issues (1)Common pitfalls and unexpected behavior

Contiguous characters in character space may not all be letters:

In[1]:=1

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https://wolfram.com/xid/0tz3ek27-ws0

Out[1]=1

In[2]:=2

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https://wolfram.com/xid/0tz3ek27-m3s

Out[2]=2

An actual script-B character is nevertheless a letter:

In[3]:=3

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https://wolfram.com/xid/0tz3ek27-q5

Out[3]=3

Neat Examples (1)Surprising or curious use cases

Plot the character codes of letters:

In[1]:=1

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https://wolfram.com/xid/0tz3ek27-fbu

Out[1]=1

Include the actual names of characters:

In[2]:=2

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https://wolfram.com/xid/0tz3ek27-i5p

Out[2]=2

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