filter

The filter function filters the contents of an array, returning only elements that match the predicate. It works in a similar way to JavaScript's Array.prototype.filter.

Syntax

<array>.filter(predicate)

Arguments

• predicate - A boolean expression evaluated against each element. Use $this to refer to the current element and $key to refer to the current index.

Examples

Filter numbers

[1, 2, 3, 4, 5].filter($this > 3)
// [4, 5]

Filter objects by a field

[
    {"name": "Alice", "age": 25},
    {"name": "Bob", "age": 17},
    {"name": "Charlie", "age": 30}
].filter(age >= 18)
// [{"name": "Alice", "age": 25}, {"name": "Charlie", "age": 30}]

CLI usage — find active users

$ cat users.json | dasel -i json 'users.filter(active == true).map(name)'

Filter by index using $key

[10, 20, 30, 40, 50].filter($key >= 2)
// [30, 40, 50]

Chained with other functions

[1, 2, 3, 4, 5].filter($this > 2).first()
// 3