### 3.2.11. Lists

Cypher has comprehensive support for lists.

 Information regarding operators such as list concatenation (`+`), element existence checking (`IN`) and access (`[]`) can be found here. The behavior of the `IN` and `[]` operators with respect to `null` is detailed here.

#### 3.2.11.1. Lists in general

A literal list is created by using brackets and separating the elements in the list with commas.

Query.

``RETURN [0, 1, 2, 3, 4, 5, 6, 7, 8, 9] AS list``

Table 3.50. Result
list

1 row

`JavaListWrapper(0, 1, 2, 3, 4, 5, 6, 7, 8, 9)`

Try this query live.  CREATE (charlie:Person {name: 'Charlie Sheen', realName: 'Carlos Irwin Estévez'}), (martin:Person {name: 'Martin Sheen'}), (wallstreet:Movie {title: 'Wall Street', year: 1987}), (reddawn:Movie {title: 'Red Dawn', year: 1984}), (apocalypsenow:Movie {title: 'Apocalypse Now', year: 1979}), (charlie)-[:ACTED_IN]->(wallstreet), (charlie)-[:ACTED_IN]->(reddawn), (charlie)-[:ACTED_IN]->(apocalypsenow), (martin)-[:ACTED_IN]->(wallstreet), (martin)-[:ACTED_IN]->(apocalypsenow) RETURN [0, 1, 2, 3, 4, 5, 6, 7, 8, 9] AS list

In our examples, we’ll use the `range` function. It gives you a list containing all numbers between given start and end numbers. Range is inclusive in both ends.

To access individual elements in the list, we use the square brackets again. This will extract from the start index and up to but not including the end index.

Query.

``RETURN range(0, 10)[3]``

Table 3.51. Result
range(0, 10)[3]

1 row

`3`

Try this query live.  CREATE (charlie:Person {name: 'Charlie Sheen', realName: 'Carlos Irwin Estévez'}), (martin:Person {name: 'Martin Sheen'}), (wallstreet:Movie {title: 'Wall Street', year: 1987}), (reddawn:Movie {title: 'Red Dawn', year: 1984}), (apocalypsenow:Movie {title: 'Apocalypse Now', year: 1979}), (charlie)-[:ACTED_IN]->(wallstreet), (charlie)-[:ACTED_IN]->(reddawn), (charlie)-[:ACTED_IN]->(apocalypsenow), (martin)-[:ACTED_IN]->(wallstreet), (martin)-[:ACTED_IN]->(apocalypsenow) RETURN range(0, 10)[3]

You can also use negative numbers, to start from the end of the list instead.

Query.

``RETURN range(0, 10)[-3]``

Table 3.52. Result
range(0, 10)[-3]

1 row

`8`

Try this query live.  CREATE (charlie:Person {name: 'Charlie Sheen', realName: 'Carlos Irwin Estévez'}), (martin:Person {name: 'Martin Sheen'}), (wallstreet:Movie {title: 'Wall Street', year: 1987}), (reddawn:Movie {title: 'Red Dawn', year: 1984}), (apocalypsenow:Movie {title: 'Apocalypse Now', year: 1979}), (charlie)-[:ACTED_IN]->(wallstreet), (charlie)-[:ACTED_IN]->(reddawn), (charlie)-[:ACTED_IN]->(apocalypsenow), (martin)-[:ACTED_IN]->(wallstreet), (martin)-[:ACTED_IN]->(apocalypsenow) RETURN range(0, 10)[-3]

Finally, you can use ranges inside the brackets to return ranges of the list.

Query.

``RETURN range(0, 10)[0..3]``

Table 3.53. Result
range(0, 10)[0..3]

1 row

`JavaListWrapper(0, 1, 2)`

Try this query live.  CREATE (charlie:Person {name: 'Charlie Sheen', realName: 'Carlos Irwin Estévez'}), (martin:Person {name: 'Martin Sheen'}), (wallstreet:Movie {title: 'Wall Street', year: 1987}), (reddawn:Movie {title: 'Red Dawn', year: 1984}), (apocalypsenow:Movie {title: 'Apocalypse Now', year: 1979}), (charlie)-[:ACTED_IN]->(wallstreet), (charlie)-[:ACTED_IN]->(reddawn), (charlie)-[:ACTED_IN]->(apocalypsenow), (martin)-[:ACTED_IN]->(wallstreet), (martin)-[:ACTED_IN]->(apocalypsenow) RETURN range(0, 10)[0..3]

Query.

``RETURN range(0, 10)[0..-5]``

Table 3.54. Result
range(0, 10)[0..-5]

1 row

`JavaListWrapper(0, 1, 2, 3, 4, 5)`

Try this query live.  CREATE (charlie:Person {name: 'Charlie Sheen', realName: 'Carlos Irwin Estévez'}), (martin:Person {name: 'Martin Sheen'}), (wallstreet:Movie {title: 'Wall Street', year: 1987}), (reddawn:Movie {title: 'Red Dawn', year: 1984}), (apocalypsenow:Movie {title: 'Apocalypse Now', year: 1979}), (charlie)-[:ACTED_IN]->(wallstreet), (charlie)-[:ACTED_IN]->(reddawn), (charlie)-[:ACTED_IN]->(apocalypsenow), (martin)-[:ACTED_IN]->(wallstreet), (martin)-[:ACTED_IN]->(apocalypsenow) RETURN range(0, 10)[0..-5]

Query.

``RETURN range(0, 10)[-5..]``

Table 3.55. Result
range(0, 10)[-5..]

1 row

`JavaListWrapper(6, 7, 8, 9, 10)`

Try this query live.  CREATE (charlie:Person {name: 'Charlie Sheen', realName: 'Carlos Irwin Estévez'}), (martin:Person {name: 'Martin Sheen'}), (wallstreet:Movie {title: 'Wall Street', year: 1987}), (reddawn:Movie {title: 'Red Dawn', year: 1984}), (apocalypsenow:Movie {title: 'Apocalypse Now', year: 1979}), (charlie)-[:ACTED_IN]->(wallstreet), (charlie)-[:ACTED_IN]->(reddawn), (charlie)-[:ACTED_IN]->(apocalypsenow), (martin)-[:ACTED_IN]->(wallstreet), (martin)-[:ACTED_IN]->(apocalypsenow) RETURN range(0, 10)[-5..]

Query.

``RETURN range(0, 10)[..4]``

Table 3.56. Result
range(0, 10)[..4]

1 row

`JavaListWrapper(0, 1, 2, 3)`

Try this query live.  CREATE (charlie:Person {name: 'Charlie Sheen', realName: 'Carlos Irwin Estévez'}), (martin:Person {name: 'Martin Sheen'}), (wallstreet:Movie {title: 'Wall Street', year: 1987}), (reddawn:Movie {title: 'Red Dawn', year: 1984}), (apocalypsenow:Movie {title: 'Apocalypse Now', year: 1979}), (charlie)-[:ACTED_IN]->(wallstreet), (charlie)-[:ACTED_IN]->(reddawn), (charlie)-[:ACTED_IN]->(apocalypsenow), (martin)-[:ACTED_IN]->(wallstreet), (martin)-[:ACTED_IN]->(apocalypsenow) RETURN range(0, 10)[..4]

 Out-of-bound slices are simply truncated, but out-of-bound single elements return `null`.

Query.

``RETURN range(0, 10)[15]``

Table 3.57. Result
range(0, 10)[15]

1 row

`<null>`

Try this query live.  CREATE (charlie:Person {name: 'Charlie Sheen', realName: 'Carlos Irwin Estévez'}), (martin:Person {name: 'Martin Sheen'}), (wallstreet:Movie {title: 'Wall Street', year: 1987}), (reddawn:Movie {title: 'Red Dawn', year: 1984}), (apocalypsenow:Movie {title: 'Apocalypse Now', year: 1979}), (charlie)-[:ACTED_IN]->(wallstreet), (charlie)-[:ACTED_IN]->(reddawn), (charlie)-[:ACTED_IN]->(apocalypsenow), (martin)-[:ACTED_IN]->(wallstreet), (martin)-[:ACTED_IN]->(apocalypsenow) RETURN range(0, 10)[15]

Query.

``RETURN range(0, 10)[5..15]``

Table 3.58. Result
range(0, 10)[5..15]

1 row

`JavaListWrapper(5, 6, 7, 8, 9, 10)`

Try this query live.  CREATE (charlie:Person {name: 'Charlie Sheen', realName: 'Carlos Irwin Estévez'}), (martin:Person {name: 'Martin Sheen'}), (wallstreet:Movie {title: 'Wall Street', year: 1987}), (reddawn:Movie {title: 'Red Dawn', year: 1984}), (apocalypsenow:Movie {title: 'Apocalypse Now', year: 1979}), (charlie)-[:ACTED_IN]->(wallstreet), (charlie)-[:ACTED_IN]->(reddawn), (charlie)-[:ACTED_IN]->(apocalypsenow), (martin)-[:ACTED_IN]->(wallstreet), (martin)-[:ACTED_IN]->(apocalypsenow) RETURN range(0, 10)[5..15]

You can get the `size` of a list as follows:

Query.

``RETURN size(range(0, 10)[0..3])``

Table 3.59. Result
size(range(0, 10)[0..3])

1 row

`3`

Try this query live.  CREATE (charlie:Person {name: 'Charlie Sheen', realName: 'Carlos Irwin Estévez'}), (martin:Person {name: 'Martin Sheen'}), (wallstreet:Movie {title: 'Wall Street', year: 1987}), (reddawn:Movie {title: 'Red Dawn', year: 1984}), (apocalypsenow:Movie {title: 'Apocalypse Now', year: 1979}), (charlie)-[:ACTED_IN]->(wallstreet), (charlie)-[:ACTED_IN]->(reddawn), (charlie)-[:ACTED_IN]->(apocalypsenow), (martin)-[:ACTED_IN]->(wallstreet), (martin)-[:ACTED_IN]->(apocalypsenow) RETURN size(range(0, 10)[0..3])

#### 3.2.11.2. List comprehension

List comprehension is a syntactic construct available in Cypher for creating a list based on existing lists. It follows the form of the mathematical set-builder notation (set comprehension) instead of the use of map and filter functions.

Query.

``RETURN [x IN range(0,10) WHERE x % 2 = 0 | x^3] AS result``

Table 3.60. Result
result

1 row

`JavaListWrapper(0.0, 8.0, 64.0, 216.0, 512.0, 1000.0)`

Try this query live.  CREATE (charlie:Person {name: 'Charlie Sheen', realName: 'Carlos Irwin Estévez'}), (martin:Person {name: 'Martin Sheen'}), (wallstreet:Movie {title: 'Wall Street', year: 1987}), (reddawn:Movie {title: 'Red Dawn', year: 1984}), (apocalypsenow:Movie {title: 'Apocalypse Now', year: 1979}), (charlie)-[:ACTED_IN]->(wallstreet), (charlie)-[:ACTED_IN]->(reddawn), (charlie)-[:ACTED_IN]->(apocalypsenow), (martin)-[:ACTED_IN]->(wallstreet), (martin)-[:ACTED_IN]->(apocalypsenow) RETURN [x IN range(0,10) WHERE x % 2 = 0 | x^3 ] AS result

Either the `WHERE` part, or the expression, can be omitted, if you only want to filter or map respectively.

Query.

``RETURN [x IN range(0,10) WHERE x % 2 = 0] AS result``

Table 3.61. Result
result

1 row

`JavaListWrapper(0, 2, 4, 6, 8, 10)`

Try this query live.  CREATE (charlie:Person {name: 'Charlie Sheen', realName: 'Carlos Irwin Estévez'}), (martin:Person {name: 'Martin Sheen'}), (wallstreet:Movie {title: 'Wall Street', year: 1987}), (reddawn:Movie {title: 'Red Dawn', year: 1984}), (apocalypsenow:Movie {title: 'Apocalypse Now', year: 1979}), (charlie)-[:ACTED_IN]->(wallstreet), (charlie)-[:ACTED_IN]->(reddawn), (charlie)-[:ACTED_IN]->(apocalypsenow), (martin)-[:ACTED_IN]->(wallstreet), (martin)-[:ACTED_IN]->(apocalypsenow) RETURN [x IN range(0,10) WHERE x % 2 = 0 ] AS result

Query.

``RETURN [x IN range(0,10)| x^3] AS result``

Table 3.62. Result
result

1 row

`JavaListWrapper(0.0, 1.0, 8.0, 27.0, 64.0, 125.0, 216.0, 343.0, 512.0, 729.0, 1000.0)`

Try this query live.  CREATE (charlie:Person {name: 'Charlie Sheen', realName: 'Carlos Irwin Estévez'}), (martin:Person {name: 'Martin Sheen'}), (wallstreet:Movie {title: 'Wall Street', year: 1987}), (reddawn:Movie {title: 'Red Dawn', year: 1984}), (apocalypsenow:Movie {title: 'Apocalypse Now', year: 1979}), (charlie)-[:ACTED_IN]->(wallstreet), (charlie)-[:ACTED_IN]->(reddawn), (charlie)-[:ACTED_IN]->(apocalypsenow), (martin)-[:ACTED_IN]->(wallstreet), (martin)-[:ACTED_IN]->(apocalypsenow) RETURN [x IN range(0,10) | x^3 ] AS result

#### 3.2.11.3. Pattern comprehension

Pattern comprehension is a syntactic construct available in Cypher for creating a list based on matchings of a pattern. A pattern comprehension will match the specified pattern just like a normal `MATCH` clause, with predicates just like a normal `WHERE` clause, but will yield a custom projection as specified.

The following graph is used for the example below:

Query.

``````MATCH (a:Person { name: 'Charlie Sheen' })
RETURN [(a)-->(b) WHERE b:Movie | b.year] AS years``````

Table 3.63. Result
years

1 row

`JavaListWrapper(1979, 1984, 1987)`

Try this query live.  CREATE (charlie:Person {name: 'Charlie Sheen', realName: 'Carlos Irwin Estévez'}), (martin:Person {name: 'Martin Sheen'}), (wallstreet:Movie {title: 'Wall Street', year: 1987}), (reddawn:Movie {title: 'Red Dawn', year: 1984}), (apocalypsenow:Movie {title: 'Apocalypse Now', year: 1979}), (charlie)-[:ACTED_IN]->(wallstreet), (charlie)-[:ACTED_IN]->(reddawn), (charlie)-[:ACTED_IN]->(apocalypsenow), (martin)-[:ACTED_IN]->(wallstreet), (martin)-[:ACTED_IN]->(apocalypsenow) MATCH (a:Person {name: 'Charlie Sheen'}) RETURN [(a)-->(b) WHERE b:Movie | b.year] AS years

The whole predicate, including the `WHERE` keyword, is optional and may be omitted.