keys() : Keys of a Dictionary or Object

Returns the keys of a dictionary, or the names of the properties of an object, as an array of text values that can be counted, sorted and enumerated.

Signature

keys(object)

Parameters

Returns

Type: Array of text

• A Dictionary<,> (or any IDictionary or read-only dictionary) returns its keys, in the order the dictionary enumerates them. Keys that are not text, such as numbers, are converted to text.
• A JSON object (Newtonsoft JObject or System.Text.Json) returns the property names, in the order they are in the JSON.
• Any other object returns the names of its public properties.
• A null value, text, a number, or an array or list has no keys, and returns an empty array.

Examples

Data:

builder.WithData("model", new {
    prices = new Dictionary<string, decimal> {
        { "Widget", 9.50m }, { "Gizmo", 3.25m }, { "Gadget", 14.00m }
    }
});

List the keys

<p>{{join(keys(model.prices), ', ')}}</p>

Output:

<p>Widget, Gizmo, Gadget</p>

Sort the keys

Sort the keys themselves with sortBy(keys(...)), and add 'desc' for descending order.

{{#each sortBy(keys(model.prices))}}
  <p>{{this}}: {{model.prices[this]}}</p>
{{/each}}

Output:

<p>Gadget: 14.00</p>
<p>Gizmo: 3.25</p>
<p>Widget: 9.50</p>

Check the number of entries

{{#if count(keys(model.prices)) > 2}}
  <p>{{count(keys(model.prices))}} prices</p>
{{else}}
  <p>Not enough prices</p>
{{/if}}

Property names of an object

<p>{{join(keys(model.person), ', ')}}</p>

With model.person as new { name = "Ann", age = 30 } this outputs name, age.

Notes

• To loop over the entries in their own order, with the value as this, use {{#each model.prices}} and @key. Use keys() when the keys need to be sorted, counted or tested first.
• Takes exactly one parameter.
• Added in Paperwork.Core 9.8.

See Also

• @key
• sortBy
• count
• join