SELECT '[1,2,3]'::vector;
 vector  
---------
 [1,2,3]
(1 row)

SELECT '[-1,-2,-3]'::vector;
   vector   
------------
 [-1,-2,-3]
(1 row)

SELECT '[1.,2.,3.]'::vector;
 vector  
---------
 [1,2,3]
(1 row)

SELECT ' [ 1,  2 ,    3  ] '::vector;
 vector  
---------
 [1,2,3]
(1 row)

SELECT '[1.23456]'::vector;
  vector   
-----------
 [1.23456]
(1 row)

SELECT '[hello,1]'::vector;
ERROR:  invalid input syntax for type vector: "[hello,1]"
LINE 1: SELECT '[hello,1]'::vector;
               ^
SELECT '[NaN,1]'::vector;
ERROR:  NaN not allowed in vector
LINE 1: SELECT '[NaN,1]'::vector;
               ^
SELECT '[Infinity,1]'::vector;
ERROR:  infinite value not allowed in vector
LINE 1: SELECT '[Infinity,1]'::vector;
               ^
SELECT '[-Infinity,1]'::vector;
ERROR:  infinite value not allowed in vector
LINE 1: SELECT '[-Infinity,1]'::vector;
               ^
SELECT '[1e38,-1e38]'::vector;
     vector     
----------------
 [1e+38,-1e+38]
(1 row)

SELECT '[1e+38,-1e+38]'::vector;
     vector     
----------------
 [1e+38,-1e+38]
(1 row)

SELECT '[1e-38,-1e-38]'::vector;
     vector     
----------------
 [1e-38,-1e-38]
(1 row)

SELECT '[4e38,1]'::vector;
ERROR:  infinite value not allowed in vector
LINE 1: SELECT '[4e38,1]'::vector;
               ^
SELECT '[1,2,3'::vector;
ERROR:  malformed vector literal: "[1,2,3"
LINE 1: SELECT '[1,2,3'::vector;
               ^
DETAIL:  Unexpected end of input.
SELECT '[1,2,3]9'::vector;
ERROR:  malformed vector literal: "[1,2,3]9"
LINE 1: SELECT '[1,2,3]9'::vector;
               ^
DETAIL:  Junk after closing right brace.
SELECT '1,2,3'::vector;
ERROR:  malformed vector literal: "1,2,3"
LINE 1: SELECT '1,2,3'::vector;
               ^
DETAIL:  Vector contents must start with "[".
SELECT '[]'::vector;
ERROR:  vector must have at least 1 dimension
LINE 1: SELECT '[]'::vector;
               ^
SELECT '[1,]'::vector;
ERROR:  invalid input syntax for type vector: "[1,]"
LINE 1: SELECT '[1,]'::vector;
               ^
SELECT '[1a]'::vector;
ERROR:  invalid input syntax for type vector: "[1a]"
LINE 1: SELECT '[1a]'::vector;
               ^
SELECT '[1,,3]'::vector;
ERROR:  malformed vector literal: "[1,,3]"
LINE 1: SELECT '[1,,3]'::vector;
               ^
SELECT '[1, ,3]'::vector;
ERROR:  invalid input syntax for type vector: "[1, ,3]"
LINE 1: SELECT '[1, ,3]'::vector;
               ^
SELECT '[1,2,3]'::vector(2);
ERROR:  expected 2 dimensions, not 3
SELECT unnest('{"[1,2,3]", "[4,5,6]"}'::vector[]);
 unnest  
---------
 [1,2,3]
 [4,5,6]
(2 rows)

SELECT '{"[1,2,3]"}'::vector(2)[];
ERROR:  expected 2 dimensions, not 3