Extract First letter from each word

Question

Hi All,
I have a requirement to extract first letter of each word as shown in below example
input: abcd output: a
input: abcd efgh output: ae
input: abcd efgh ijkl output: aejany help will be highly appreciated
I am on db version 11g

Answer 1

jeneesh wrote:
Just a note - This will not take care of spaces at the end of the line..You're right, and not just spaces but any non-word characters. Here is fixed solution:
with t as (
           select 'abcd ' str from dual union all
           select 'abcd efgh.' from dual union all
           select 'abcd efgh ijkl,' from dual union all
           select ' a abcd efgh ijkl! ' from dual
select  str,
        '[' || regexp_replace(str,'\W*(\w)(\w*)|(\W*$)','\1') || ']' initials
  from  t
STR                 INITIALS
abcd                [a]
abcd efgh.          [ae]
abcd efgh ijkl,     [aei]
a abcd efgh ijkl!  [aaei]
SQL> BTW, oldie_63's solution takes care of spaces but not:
with t as (
           select ' abcd' str from dual union all
           select '.abcd efgh' from dual union all
           select ',abcd efgh ijkl' from dual union all
           select '! a abcd efgh ijkl' from dual
select  str,
        '[' || trim(regexp_replace(str,'(\S)\S*\s*','\1')) || ']' initials
  from  t
STR                INITIALS
abcd              [a]
.abcd efgh         [.e]
,abcd efgh ijkl    [,ei]
! a abcd efgh ijkl [!aaei]
SQL> Also, OP needs to clarify what to do with hyphenated words:
SQL> with t as (
  2             select 'sugar-free' str from dual
  3            )
  4  select  str,
  5          '[' || regexp_replace(str,'\W*(\w)(\w*)|(\W*$)','\1') || ']' initials
  6    from  t
  7  /
STR        INITIALS
sugar-free [sf]
SQL> with t as (
  2             select 'sugar-free' str from dual
  3            )
  4  select  str,
  5          '[' || trim(regexp_replace(str,'(\S)\S*\s*','\1')) || ']' initials
  6    from  t
  7  /
STR        INITIALS
sugar-free [s]
SQL>Or words like:
SQL> with t as (
  2             select 'O''Reily' str from dual
  3            )
  4  select  str,
  5          '[' || regexp_replace(str,'\W*(\w)(\w*)|(\W*$)','\1') || ']' initials
  6    from  t
  7  /
STR     INITIALS
O'Reily [OR]
SQL> with t as (
  2             select 'O''Reily' str from dual
  3            )
  4  select  str,
  5          '[' || regexp_replace(str,'\W*(\w)(\w*)|(\W*$)','\1') || ']' initials
  6    from  t
  7  /
STR     INITIALS
O'Reily [OR]
SQL> SY.