---
title: bool() function
description: >
  `bool()` converts a value to a boolean type.
menu:
  flux_v0_ref:
    name: bool
    parent: universe
    identifier: universe/bool
weight: 101
flux/v0/tags: [type-conversions]
introduced: 0.7.0
---

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`bool()` converts a value to a boolean type.



##### Function type signature

```js
(v: A) => bool
```

{{% caption %}}
For more information, see [Function type signatures](/flux/v0/function-type-signatures/).
{{% /caption %}}

## Parameters

### v
({{< req >}})
Value to convert.




## Examples

- [Convert strings to booleans](#convert-strings-to-booleans)
- [Convert numeric values to booleans](#convert-numeric-values-to-booleans)
- [Convert all values in a column to booleans](#convert-all-values-in-a-column-to-booleans)

### Convert strings to booleans

```js
bool(v: "true")

// Returns true
bool(v: "false")// Returns false


```


### Convert numeric values to booleans

```js
bool(v: 1.0)

// Returns true
bool(v: 0.0)

// Returns false
bool(v: 1)

// Returns true
bool(v: 0)

// Returns false
bool(v: uint(v: 1))

// Returns true
bool(v: uint(v: 0))// Returns false


```


### Convert all values in a column to booleans

If converting the `_value` column to boolean types, use `toBool()`.
If converting columns other than `_value`, use `map()` to iterate over each
row and `bool()` to convert a column value to a boolean type.

```js
data
    |> map(fn: (r) => ({r with powerOn: bool(v: r.powerOn)}))

```

{{< expand-wrapper >}}
{{% expand "View example input and output" %}}

#### Input data

| _time                | powerOn  | *tag |
| -------------------- | -------- | ---- |
| 2021-01-01T00:00:00Z | 1        | t1   |
| 2021-01-01T00:00:10Z | 1        | t1   |
| 2021-01-01T00:00:20Z | 0        | t1   |
| 2021-01-01T00:00:30Z | 1        | t1   |
| 2021-01-01T00:00:40Z | 0        | t1   |
| 2021-01-01T00:00:50Z | 0        | t1   |

| _time                | powerOn  | *tag |
| -------------------- | -------- | ---- |
| 2021-01-01T00:00:00Z | 0        | t2   |
| 2021-01-01T00:00:10Z | 1        | t2   |
| 2021-01-01T00:00:20Z | 0        | t2   |
| 2021-01-01T00:00:30Z | 1        | t2   |
| 2021-01-01T00:00:40Z | 1        | t2   |
| 2021-01-01T00:00:50Z | 0        | t2   |


#### Output data

| _time                | powerOn  | *tag |
| -------------------- | -------- | ---- |
| 2021-01-01T00:00:00Z | true     | t1   |
| 2021-01-01T00:00:10Z | true     | t1   |
| 2021-01-01T00:00:20Z | false    | t1   |
| 2021-01-01T00:00:30Z | true     | t1   |
| 2021-01-01T00:00:40Z | false    | t1   |
| 2021-01-01T00:00:50Z | false    | t1   |

| _time                | powerOn  | *tag |
| -------------------- | -------- | ---- |
| 2021-01-01T00:00:00Z | false    | t2   |
| 2021-01-01T00:00:10Z | true     | t2   |
| 2021-01-01T00:00:20Z | false    | t2   |
| 2021-01-01T00:00:30Z | true     | t2   |
| 2021-01-01T00:00:40Z | true     | t2   |
| 2021-01-01T00:00:50Z | false    | t2   |

{{% /expand %}}
{{< /expand-wrapper >}}