mapValues

The mapValues function transforms all values of a map/object while preserving its keys. It is the map/object counterpart to map, which operates on arrays.

Syntax

<object>.mapValues(expr)

Arguments

• expr - An expression evaluated against each value. Use $this to refer to the current value and $key to refer to the current key name.

Examples

Double all values

{"a": 1, "b": 2, "c": 3}.mapValues($this * 2)
// {"a": 2, "b": 4, "c": 6}

Boolean expression

{"a": 3, "b": 8}.mapValues($this > 5)
// {"a": false, "b": true}

Transform strings

{"x": "hello", "y": "world"}.mapValues(toUpper())
// {"x": "HELLO", "y": "WORLD"}

Replace values with their key names using $key

{"a": 1, "b": 2}.mapValues($key)
// {"a": "a", "b": "b"}

CLI usage

$ echo '{"a":1,"b":2}' | dasel 'mapValues($this * 2)'
{
    "a": 2,
    "b": 4
}

Chained with property access

{"a": 1, "b": 2}.mapValues($this + 10).a
// 11