npm package: @stdlib/math-base-assert-is-nonpositive-integer
Description: Test if a finite double-precision floating-point number is a nonpositive integer.
Author: The Stdlib Authors
Latest version: 0.2.3

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# isNonPositiveInteger

[![NPM version][npm-image]][npm-url] [![Build Status][test-image]][test-url] [![Coverage Status][coverage-image]][coverage-url] <!-- [![dependencies][dependencies-image]][dependencies-url] -->

> Test if a finite [double-precision floating-point number][ieee754] is a nonpositive integer.

<section class="installation">

## Installation

```bash
npm install @stdlib/math-base-assert-is-nonpositive-integer
```

</section>

<section class="usage">

## Usage

```javascript
var isNonPositiveInteger = require( '@stdlib/math-base-assert-is-nonpositive-integer' );
```

#### isNonPositiveInteger( x )

Tests if a finite [double-precision floating-point number][ieee754] is a nonpositive integer.

```javascript
var bool = isNonPositiveInteger( -1.0 );
// returns true

bool = isNonPositiveInteger( 0.0 );
// returns true

bool = isNonPositiveInteger( 10.0 );
// returns false
```

</section>

<!-- /.usage -->

<section class="notes">

## Notes

-   The function assumes a **finite** `number`. If provided negative `infinity`, the function will return `true`, when, in fact, the result is undefined. If `x` can be `infinite`, wrap the implementation as follows:

    ```javascript
    function check( x ) {
        return (
            x > -Infinity &&
            isNonPositiveInteger( x )
        );
    }

    var bool = check( -Infinity );
    // returns false
    ```

-   The function does **not** distinguish between positive and negative `zero`.

    ```javascript
    var bool = isNonPositiveInteger( 0.0 );
    // returns true

    bool = isNonPositiveInteger( -0.0 );
    // returns true
    ```

</section>

<!-- /.notes -->

<section class="examples">

## Examples

<!-- eslint no-undef: "error" -->

```javascript
var isNonPositiveInteger = require( '@stdlib/math-base-assert-is-nonpositive-integer' );

var bool = isNonPositiveInteger( -5.0 );
// returns true

bool = isNonPositiveInteger( 0.0 );
// returns true

bool = isNonPositiveInteger( 1.0 );
// returns false

bool = isNonPositiveInteger( -3.14 );
// returns false

bool = isNonPositiveInteger( NaN );
// returns false
```

</section>

<!-- /.examples -->

<!-- C interface documentation. -->

* * *

<section class="c">

## C APIs

<!-- Section to include introductory text. Make sure to keep an empty line after the intro `section` element and another before the `/section` close. -->

<section class="intro">

</section>

<!-- /.intro -->

<!-- C usage documentation. -->

<section class="usage">

### Usage

```c
#include "stdlib/math/base/assert/is_nonpositive_integer.h"
```

#### stdlib_base_is_nonpositive_integer( x )

Tests if a finite double-precision floating-point number is a nonpositive integer.

```c
#include <stdbool.h>

bool out = stdlib_base_is_nonpositive_integer( -5.0 );
// returns true

out = stdlib_base_is_nonpositive_integer( 0.0 );
// returns true
```

The function accepts the following arguments:

-   **x**: `[in] double` input value.

```c
bool stdlib_base_is_nonpositive_integer( const double x );
```

</section>

<!-- /.usage -->

<!-- C API usage notes. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->

<section class="notes">

</section>

<!-- /.notes -->

<!-- C API usage examples. -->

<section class="examples">

### Examples

```c
#include "stdlib/math/base/assert/is_nonpositive_integer.h"
#include <stdio.h>
#include <stdbool.h>

int main( void ) {
    const double x[] = { 5.0, -5.0, 3.14, -3.14, 0.0, 0.0/0.0 };

    bool b;
    int i;
    for ( i = 0; i < 6; i++ ) {
        b = stdlib_base_is_nonpositive_integer( x[ i ] );
        printf( "x = %lf, is_nonpositive_integer(x) = %s\n", x[ i ], ( b ) ? "True" : "False" );
    }
}
```

</section>

<!-- /.examples -->

</section>

<!-- /.c -->

<!-- Section for related `stdlib` packages. Do not manually edit this section, as it is automatically populated. -->

<section class="related">

* * *

## See Also

-   <span class="package-name">[`@stdlib/math-base/assert/is-integer`][@stdlib/math/base/assert/is-integer]</span><span class="delimiter">: </span><span class="description">test if a finite double-precision floating-point number is an integer.</span>
-   <span class="package-name">[`@stdlib/math-base/assert/is-negative-integer`][@stdlib/math/base/assert/is-negative-integer]</span><span class="delimiter">: </span><span class="description">test if a finite double-precision floating-point number is a negative integer.</span>
-   <span class="package-name">[`@stdlib/math-base/assert/is-nonnegative-integer`][@stdlib/math/base/assert/is-nonnegative-integer]</span><span class="delimiter">: </span><span class="description">test if a finite double-precision floating-point number is a nonnegative integer.</span>
-   <span class="package-name">[`@stdlib/math-base/assert/is-positive-integer`][@stdlib/math/base/assert/is-positive-integer]</span><span class="delimiter">: </span><span class="description">test if a finite double-precision floating-point number is a positive integer.</span>

</section>

<!-- /.related -->

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<section class="main-repo" >

* * *

## Notice

This package is part of [stdlib][stdlib], a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.

For more information on the project, filing bug reports and feature requests, and guidance on how to develop [stdlib][stdlib], see the main project [repository][stdlib].

#### Community

[![Chat][chat-image]][chat-url]

---

## License

See [LICENSE][stdlib-license].


## Copyright

Copyright &copy; 2016-2026. The Stdlib [Authors][stdlib-authors].

</section>

<!-- /.stdlib -->

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[ieee754]: https://en.wikipedia.org/wiki/IEEE_754-1985

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[@stdlib/math/base/assert/is-integer]: https://www.npmjs.com/package/@stdlib/math-base-assert-is-integer

[@stdlib/math/base/assert/is-negative-integer]: https://www.npmjs.com/package/@stdlib/math-base-assert-is-negative-integer

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[@stdlib/math/base/assert/is-positive-integer]: https://www.npmjs.com/package/@stdlib/math-base-assert-is-positive-integer

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