About stdlib...

We believe in a future in which the web is a preferred environment for numerical computation. To help realize this future, we've built stdlib. stdlib is a standard library, with an emphasis on numerical and scientific computation, written in JavaScript (and C) for execution in browsers and in Node.js.

The library is fully decomposable, being architected in such a way that you can swap out and mix and match APIs and functionality to cater to your exact preferences and use cases.

When you use stdlib, you can be absolutely certain that you are using the most thorough, rigorous, well-written, studied, documented, tested, measured, and high-quality code out there.

To join us in bringing numerical computing to the web, get started by checking us out on GitHub, and please consider financially supporting stdlib. We greatly appreciate your continued support!

isTriangularNumber

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

> Test if a value is a [triangular number][triangular-number].

[Triangular numbers][triangular-number] can be computed using the following formula

-->

for n >= 0.

By analogy with the square root of x, one can define the positive triangular root of x such that T_n = x

Accordingly, an integer x is a [triangular number][triangular-number] if and only if 8x+1 is a [square number][@stdlib/assert/is-square-number].

Installation

``bash npm install @stdlib/assert-is-triangular-number`

`Usage`

`javascript var isTriangularNumber = require( '@stdlib/assert-is-triangular-number' );`

#### isTriangularNumber( value )

Tests if a value is a [triangular number][triangular-number].

`javascript var Number = require( '@stdlib/number-ctor' );

var bool = isTriangularNumber( 36.0 ); // returns true

bool = isTriangularNumber( new Number( 36.0 ) ); // returns true

bool = isTriangularNumber( 3.14 ); // returns false

bool = isTriangularNumber( -5.0 ); // returns false

bool = isTriangularNumber( NaN ); // returns false

bool = isTriangularNumber( null ); // returns false`

#### isTriangularNumber.isPrimitive( value )

Tests if a value is a primitive [triangular number][triangular-number].

`javascript var Number = require( '@stdlib/number-ctor' );

var bool = isTriangularNumber.isPrimitive( 36.0 ); // returns true

bool = isTriangularNumber.isPrimitive( new Number( 36.0 ) ); // returns false`

#### isTriangularNumber.isObject( value )

Tests if a value is a Number object having a value which is a [triangular number][triangular-number].

`javascript var Number = require( '@stdlib/number-ctor' );

var bool = isTriangularNumber.isObject( 36.0 ); // returns false

bool = isTriangularNumber.isObject( new Number( 36.0 ) ); // returns true`

`Notes`

- Return values are not reliable for numbers greater than 1125899906842624.

`Examples`

`javascript var Number = require( '@stdlib/number-ctor' ); var isTriangularNumber = require( '@stdlib/assert-is-triangular-number' );

var bool = isTriangularNumber( 36.0 ); // returns true

bool = isTriangularNumber( new Number( 36.0 ) ); // returns true

bool = isTriangularNumber( 0.0 ); // returns true

bool = isTriangularNumber( 1.0 ); // returns true

bool = isTriangularNumber( 3.14 ); // returns false

bool = isTriangularNumber( -5.0 ); // returns false

bool = isTriangularNumber( NaN ); // returns false

bool = isTriangularNumber( '0.5' ); // returns false

bool = isTriangularNumber( null ); // returns false`

*

`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`

[npm-image]: http://img.shields.io/npm/v/@stdlib/assert-is-triangular-number.svg [npm-url]: https://npmjs.org/package/@stdlib/assert-is-triangular-number

[test-image]: https://github.com/stdlib-js/assert-is-triangular-number/actions/workflows/test.yml/badge.svg?branch=v0.2.3 [test-url]: https://github.com/stdlib-js/assert-is-triangular-number/actions/workflows/test.yml?query=branch:v0.2.3

[coverage-image]: https://img.shields.io/codecov/c/github/stdlib-js/assert-is-triangular-number/main.svg [coverage-url]: https://codecov.io/github/stdlib-js/assert-is-triangular-number?branch=main

[chat-image]: https://img.shields.io/badge/zulip-join_chat-brightgreen.svg [chat-url]: https://stdlib.zulipchat.com

[stdlib]: https://github.com/stdlib-js/stdlib

[stdlib-authors]: https://github.com/stdlib-js/stdlib/graphs/contributors

[umd]: https://github.com/umdjs/umd [es-module]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Modules

[deno-url]: https://github.com/stdlib-js/assert-is-triangular-number/tree/deno [deno-readme]: https://github.com/stdlib-js/assert-is-triangular-number/blob/deno/README.md [umd-url]: https://github.com/stdlib-js/assert-is-triangular-number/tree/umd [umd-readme]: https://github.com/stdlib-js/assert-is-triangular-number/blob/umd/README.md [esm-url]: https://github.com/stdlib-js/assert-is-triangular-number/tree/esm [esm-readme]: https://github.com/stdlib-js/assert-is-triangular-number/blob/esm/README.md [branches-url]: https://github.com/stdlib-js/assert-is-triangular-number/blob/main/branches.md

[stdlib-license]: https://raw.githubusercontent.com/stdlib-js/assert-is-triangular-number/main/LICENSE

[triangular-number]: https://en.wikipedia.org/wiki/Triangular_number

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

[@stdlib/assert/is-number]: https://www.npmjs.com/package/@stdlib/assert-is-number

[@stdlib/assert/is-square-number]: https://www.npmjs.com/package/@stdlib/assert-is-square-number

[@stdlib/assert/is-square-triangular-number]: https://www.npmjs.com/package/@stdlib/assert-is-square-triangular-number


  
    About stdlib...
  

  We believe in a future in which the web is a preferred environment for numerical computation. To help realize this future, we've built stdlib. stdlib is a standard library, with an emphasis on numerical and scientific computation, written in JavaScript (and C) for execution in browsers and in Node.js.

  The library is fully decomposable, being architected in such a way that you can swap out and mix and match APIs and functionality to cater to your exact preferences and use cases.

  When you use stdlib, you can be absolutely certain that you are using the most thorough, rigorous, well-written, studied, documented, tested, measured, and high-quality code out there.

  To join us in bringing numerical computing to the web, get started by checking us out on GitHub, and please consider financially supporting stdlib. We greatly appreciate your continued support!

`isTriangularNumber`

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

> Test if a value is a [triangular number][triangular-number].

[Triangular numbers][triangular-number] can be computed using the following formula

 -->
for n >= 0.
By analogy with the square root of x, one can define the positive triangular root of x such that T_n = x
Accordingly, an integer x is a [triangular number][triangular-number] if and only if 8x+1 is a [square number][@stdlib/assert/is-square-number].

`Installation`

``bash npm install @stdlib/assert-is-triangular-number `

`Usage`

`javascript var isTriangularNumber = require( '@stdlib/assert-is-triangular-number' ); `

#### isTriangularNumber( value )

Tests if a value is a [triangular number][triangular-number].

`javascript var Number = require( '@stdlib/number-ctor' );

var bool = isTriangularNumber( 36.0 ); // returns true

bool = isTriangularNumber( new Number( 36.0 ) ); // returns true

bool = isTriangularNumber( 3.14 ); // returns false

bool = isTriangularNumber( -5.0 ); // returns false

bool = isTriangularNumber( NaN ); // returns false

bool = isTriangularNumber( null ); // returns false `

#### isTriangularNumber.isPrimitive( value )

Tests if a value is a primitive [triangular number][triangular-number].

`javascript var Number = require( '@stdlib/number-ctor' );

var bool = isTriangularNumber.isPrimitive( 36.0 ); // returns true

bool = isTriangularNumber.isPrimitive( new Number( 36.0 ) ); // returns false `

#### isTriangularNumber.isObject( value )

Tests if a value is a Number object having a value which is a [triangular number][triangular-number].

`javascript var Number = require( '@stdlib/number-ctor' );

var bool = isTriangularNumber.isObject( 36.0 ); // returns false

bool = isTriangularNumber.isObject( new Number( 36.0 ) ); // returns true `

`Notes`

- Return values are not reliable for numbers greater than 1125899906842624.

`Examples`

`javascript var Number = require( '@stdlib/number-ctor' ); var isTriangularNumber = require( '@stdlib/assert-is-triangular-number' );