---
title: "Operators | Grafana Agent documentation"
description: "Learn about operators"
---

# Operators

River uses a common set of operators. All operations follow the standard [PEMDAS](https://en.wikipedia.org/wiki/Order_of_operations) order of mathematical operations.

## Arithmetic operators

Expand table

| Operator | Description                                        |
|----------|----------------------------------------------------|
| `+`      | Adds two numbers.                                  |
| `-`      | Subtracts two numbers.                             |
| `*`      | Multiplies two numbers.                            |
| `/`      | Divides two numbers.                               |
| `%`      | Computes the remainder after dividing two numbers. |
| `^`      | Raises the number to the specified power.          |

## String operators

Expand table

| Operator | Description              |
|----------|--------------------------|
| `+`      | Concatenate two strings. |

## Comparison operators

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| Operator | Description                                                          |
|----------|----------------------------------------------------------------------|
| `==`     | `true` when two values are equal.                                    |
| `!=`     | `true` when two values aren’t equal.                                 |
| `<`      | `true` when the left value is less than the right value.             |
| `<=`     | `true` when the left value is less than or equal to the right value. |
| `>`      | `true` when the left value is greater than the right value.          |
| `>=`     | `true` when the left value is greater or equal to the right value.   |

You can apply the equality operators `==` and `!=` to any operands.

The two operands in ordering operators `<` `<=` `>` and `>=` must both be *orderable* and of the same type. The results of the comparisons are:

- Boolean values are equal if they’re either both true or both false.
- Numerical (integer and floating-point) values are orderable in the usual way.
- String values are orderable lexically byte-wise.
- Objects are equal if all their fields are equal.
- Array values are equal if their corresponding elements are equal.

## Logical operators

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| Operator | Description                                              |
|----------|----------------------------------------------------------|
| `&&`     | `true` when the both left *and* right value are `true`.  |
| `||`     | `true` when the either left *or* right value are `true`. |
| `!`      | Negates a boolean value.                                 |

Logical operators apply to boolean values and yield a boolean result.

## Assignment operator

River uses `=` as its assignment operator.

An assignment statement may only assign a single value. Each value must be *assignable* to the attribute or object key.

- You can assign `null` to any attribute.
- You can assign numerical, string, boolean, array, function, capsule, and object types to attributes of the corresponding type.
- You can assign numbers to string attributes with an implicit conversion.
- You can assign strings to numerical attributes if they represent a number.
- You can’t assign blocks.

## Brackets

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| Brackets | Description                         |
|----------|-------------------------------------|
| `{ }`    | Defines blocks and objects.         |
| `( )`    | Groups and prioritizes expressions. |
| `[ ]`    | Defines arrays.                     |

The following example uses curly braces and square brackets to define an object and an array.

Alloy ![Copy code to clipboard](/media/images/icons/icon-copy-small-2.svg) Copy

```alloy
obj = { app = "agent", namespace = "dev" }
arr = [1, true, 7 * (1+1), 3]
```

## Access operators

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| Operator | Description                                                             |
|----------|-------------------------------------------------------------------------|
| `[ ]`    | Access a member of an array or object.                                  |
| `.`      | Access a named member of an object or an exported field of a component. |

You can access arbitrarily nested values with River’s access operators. You can use square brackets to access zero-indexed array indices and object fields by enclosing the field name in double quotes. You can use the dot operator to access object fields without double quotes and component exports.

Alloy ![Copy code to clipboard](/media/images/icons/icon-copy-small-2.svg) Copy

```alloy
obj["app"]
arr[1]

obj.app
local.file.token.content
```

If you use the `[ ]` operator to access a member of an object where the member doesn’t exist, the resulting value is `null`.

If you use the `.` operator to access a named member of an object where the named member doesn’t exist, an error is generated.