---
title: sum
description: "Add numeric array values or numeric object properties."
---

# sum

Add numeric array values or numeric object properties.

## Syntax

```knap
{{ value | sum }}
{{ value | sum:"amount" }}
{{ value | sum:"details.amount" }}
```

## Usage

- Without a parameter, numeric array items are added.
- Pass a quoted property path to add values from object items. Dotted paths select nested own properties.
- Finite numbers and nonblank numeric strings are included. Missing properties, blank strings, nonnumeric values, and infinities are ignored.
- An empty array returns `0`.

## Examples

### Numeric values

```json title="Data"
{
  "values": [
    10,
    "2.5",
    "",
    "none"
  ]
}
```

```knap title="Template"
{{ values | sum }}
```

```md title="Output"
12.5
```

### Object property

```json title="Data"
{
  "items": [
    {
      "amount": 10
    },
    {
      "amount": "2.5"
    },
    {}
  ]
}
```

```knap title="Template"
{{ items | sum:"amount" }}
```

```md title="Output"
12.5
```

## Related filters

- [map](/filters/map)
- [where](/filters/where)