neo4j: What is the syntax to set cypher query parameters in the browser interface?

In neo4j-browser you need type for example:

:params {nodes: [{name: "John", age: 18}, {name: "Phill", age: 23}]}

Then you can use params as usual:

UNWIND {nodes} as node
MERGE (A:User {name: node.name, age: node.age})
RETURN A

For clear params in neo4j-browser type :params {}.

For additional help type :help params.

In Neo4j-3.3.4, the cypher likes this:

:param nodes: [{name: 'John', age: 18}, {name: 'Phill', age: 23}]

Neo4j Browser result: here

In Neo4j Browser 3.5+ you can use the Cypher Shell parameter syntax, documented here: https://neo4j.com/docs/operations-manual/3.5/tools/cypher-shell/#cypher-shell-parameters

:param name => expression

The expression must be kept on a single line.

The expression could be a scalar or a list:

:param foo => ['a', 'b', 'c']

Maps can't be used directly with this syntax as of Neo4j 4.1. You can wrap them into a list:

:param foo => [{name: 'Alice', age: 38, address: {city: 'London', residential: true}}] 

Or you can use :params:

:params {foo: {name: 'Alice', age: 38, address: {city: 'London', residential: true}}}