{"id":16055761,"url":"https://github.com/varunsridharan/js-is","last_synced_at":"2025-07-05T05:36:30.410Z","repository":{"id":80544295,"uuid":"299809275","full_name":"varunsridharan/js-is","owner":"varunsridharan","description":"ES6 JavaScript Type Check Library ","archived":false,"fork":false,"pushed_at":"2020-10-18T14:59:41.000Z","size":19,"stargazers_count":0,"open_issues_count":0,"forks_count":1,"subscribers_count":1,"default_branch":"main","last_synced_at":"2025-06-11T19:13:04.599Z","etag":null,"topics":["es6","es6-javascript","isjs","javascript","javascript-checkers","javascript-ischeck","javascript-istype","javascript-library","javascript-type","javascript-typecheck","js-istype","js-lib","js-library","js-type","jsis","typecheck","typechecker"],"latest_commit_sha":null,"homepage":"","language":"JavaScript","has_issues":true,"has_wiki":null,"has_pages":null,"mirror_url":null,"source_name":null,"license":null,"status":null,"scm":"git","pull_requests_enabled":true,"icon_url":"https://github.com/varunsridharan.png","metadata":{"files":{"readme":"README.md","changelog":"CHANGELOG.md","contributing":null,"funding":null,"license":null,"code_of_conduct":null,"threat_model":null,"audit":null,"citation":null,"codeowners":null,"security":null,"support":null,"governance":null,"roadmap":null,"authors":null,"dei":null,"publiccode":null,"codemeta":null},"funding":{"github":["varunsridharan"],"patreon":null,"open_collective":null,"ko_fi":null,"tidelift":null,"custom":["https://paypal.me/varunsridharan23","https://www.buymeacoffee.com/varunsridharan"]}},"created_at":"2020-09-30T04:32:49.000Z","updated_at":"2023-04-11T15:32:17.000Z","dependencies_parsed_at":"2023-09-06T07:15:26.957Z","dependency_job_id":null,"html_url":"https://github.com/varunsridharan/js-is","commit_stats":null,"previous_names":[],"tags_count":1,"template":false,"template_full_name":null,"purl":"pkg:github/varunsridharan/js-is","repository_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/varunsridharan%2Fjs-is","tags_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/varunsridharan%2Fjs-is/tags","releases_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/varunsridharan%2Fjs-is/releases","manifests_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/varunsridharan%2Fjs-is/manifests","owner_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners/varunsridharan","download_url":"https://codeload.github.com/varunsridharan/js-is/tar.gz/refs/heads/main","sbom_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/varunsridharan%2Fjs-is/sbom","host":{"name":"GitHub","url":"https://github.com","kind":"github","repositories_count":263691541,"owners_count":23496873,"icon_url":"https://github.com/github.png","version":null,"created_at":"2022-05-30T11:31:42.601Z","updated_at":"2022-07-04T15:15:14.044Z","host_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub","repositories_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories","repository_names_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repository_names","owners_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners"}},"keywords":["es6","es6-javascript","isjs","javascript","javascript-checkers","javascript-ischeck","javascript-istype","javascript-library","javascript-type","javascript-typecheck","js-istype","js-lib","js-library","js-type","jsis","typecheck","typechecker"],"created_at":"2024-10-09T02:21:54.955Z","updated_at":"2025-07-05T05:36:30.387Z","avatar_url":"https://github.com/varunsridharan.png","language":"JavaScript","funding_links":["https://github.com/sponsors/varunsridharan","https://paypal.me/varunsridharan23","https://www.buymeacoffee.com/varunsridharan"],"categories":[],"sub_categories":[],"readme":"# JS IS\nES6 JavaScript Type Check Library.\n\n## ⚙️Installation\nThe preferred way to install this extension is through [NPM][NPM].\n\n    $ npm install @varunsridharan/js-is --save-dev\n\n\n## 🚀 Usage\n\n```javascript\nimport { isUndefined } from \"@varunsridharan/js-is\"\nvar var1 = 'your-value';\n\nif( isUndefined(var1) ){\n    alert('Var1 is defined')\n}\n\nif( isUndefined(var2) ){\n    alert('Var1 is defined')\n} else {\n    alert('Var2 is NOT defined')\n}\n```\n\n## 🏗 Functions\n### `isNull`\n```javascript  \nimport { isNull } from \"@varunsridharan/js-is\"\n\nisNull( null ); // true\n\nisNull( 42 ); // false\n```\n\n### `isObject`\n```javascript  \nimport { isObject } from \"@varunsridharan/js-is\"\n\nisObject( { foo: 'bar' } ); // true\n\nisObject( null ); // false\n\nisObject( 'foo' ); // false\n```\n\n### `isArguments`\n```javascript  \nimport { isArguments } from \"@varunsridharan/js-is\"\n\nvar getArguments = function() {\n\treturn arguments;\n};\n\nisArguments( getArguments() ); // true\n\nisArguments( { foo: 'bar' } ); // false\n```\n\n### `isArray`\n```javascript  \nimport { isArray } from \"@varunsridharan/js-is\"\n\nisArray( ['foo', 'bar', 'baz'] ); // true\n\nisArray( {foo: 'bar'} ); // false\n```\n\n### `isBoolean`\n```javascript  \nimport { isBoolean } from \"@varunsridharan/js-is\"\n\nisBoolean( true ); // true\n\nisBoolean( false ); // true\n\nisBoolean( 'value' ); // false\n```\n\n### `isTrue`\n```javascript  \nimport { isTrue } from \"@varunsridharan/js-is\"\n\nisTrue( true ); // true\n\nisTrue( false ); // false\n```\n\n### `isFalse`\n```javascript  \nimport { isFalse } from \"@varunsridharan/js-is\"\n\nisFalse( false ); // true\n\nisFalse( true ); // false\n```\n\n### `isDate`\n```javascript  \nimport { isDate } from \"@varunsridharan/js-is\"\n\nisDate( new Date() ); // true\n\nisDate( '20/09/2020' ); // false\n```\n\n### `isError`\n```javascript  \nimport { isError } from \"@varunsridharan/js-is\"\n\nisError( new Error() ); // true\n\nisError( 'unknown error' ); // false\n```\n\n### `isFunction`\n```javascript  \nimport { isFunction } from \"@varunsridharan/js-is\"\n\nconst tolowercase = ( string ) =\u003e String.toLowerCase.call( string );\n\nfunction myfunction() {\n\treturn 'Nothing';\n}\n\nisFunction( toString ); // true\n\nisFunction( tolowercase ); // true\n\nisFunction( myfunction ); // true\n\nisFunction( { foo: bar } ); // false\n```\n\n### `isNan`\n```javascript  \nimport { isNan } from \"@varunsridharan/js-is\"\n\nisNan( NaN ); // true\n\nisNan( 1 ); // false\n\nisNan( '1' ); // false\n```\n\n### `isNull`\n```javascript  \nimport { isNan } from \"@varunsridharan/js-is\"\n\nisNull( null ); // true\n\nisNull( 1 ); // false\n\nisNull( '1' ); // false\n```\n\n### `isNumber`\n```javascript  \nimport { isNumber } from \"@varunsridharan/js-is\"\n\nisNumber( 42 ); // true\n\nisNumber( '42' ); // false\n\nisNumber( NaN ); // false\n```\n\n### `isNumeric`\n```javascript  \nimport { isNumeric } from \"@varunsridharan/js-is\"\n\nisNumeric( 42 ); // true\n\nisNumeric( '42' ); // true\n\nisNumeric( NaN ); // false\n```\n\n### `isString`\n```javascript  \nimport { isNumeric } from \"@varunsridharan/js-is\"\n\nisNumeric( '42' ); // true\n\nisNumeric( 'your-string' ); // true\n\nisNumeric( 42 ); // false\n\nisNumeric( NaN ); // false\n```\n\n### `isUndefined`\n```javascript  \nimport { isUndefined } from \"@varunsridharan/js-is\"\n\nconst var2 = 'somevalue';\n\nisUndefined( var1 ); // true\n\nisUndefined( var2 ); // false\n\nisUndefined( 'your-string' ); // false\n```\n\n### `isPlainObject`\n```javascript  \nimport { isPlainObject } from \"@varunsridharan/js-is\"\n\nisPlainObject( {} ); // true\n\nisUndefined( var2 ); // false\n\nisUndefined( 'your-string' ); // false\n```\n\n### `isWindow`\n```javascript\nimport { isWindow } from \"@varunsridharan/js-is\"\n\nisWindow( window ); // true\n\nisWindow( document ); // false\n```\n\n### `isElement`\n```javascript\nimport { isDocument } from \"@varunsridharan/js-is\"\n\nisDocument( yourelem ); // true\n\nisDocument( 'window' ); // false\n```\n\n### `isDocument`\n```javascript\nimport { isDocument } from \"@varunsridharan/js-is\"\n\nisDocument( document ); // true\n\nisDocument( window ); // false\n```\n\n---\n\n## 📝 Changelog\nAll notable changes to this project will be documented in this file.\n\nThe format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),\nand this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).\n\n[Checkout CHANGELOG.md](/CHANGELOG.md)\n\n## 🤝 Contributing\nIf you would like to help, please take a look at the list of [issues](issues/).\n\n## 💰 Sponsor\n[I][twitter] fell in love with open-source in 2013 and there has been no looking back since! You can read more about me [here][website].\nIf you, or your company, use any of my projects or like what I’m doing, kindly consider backing me. I'm in this for the long run.\n\n- ☕ How about we get to know each other over coffee? Buy me a cup for just [**$9.99**][buymeacoffee]\n- ☕️☕️ How about buying me just 2 cups of coffee each month? You can do that for as little as [**$9.99**][buymeacoffee]\n- 🔰         We love bettering open-source projects. Support 1-hour of open-source maintenance for [**$24.99 one-time?**][paypal]\n- 🚀         Love open-source tools? Me too! How about supporting one hour of open-source development for just [**$49.99 one-time ?**][paypal]\n\n## 📜  License \u0026 Conduct\n- [**General Public License v3.0 license**](LICENSE) © [Varun Sridharan](website)\n- [Code of Conduct](code-of-conduct.md)\n\n## 📣 Feedback\n- ⭐ This repository if this project helped you! :wink:\n- Create An [🔧 Issue](issues/) if you need help / found a bug\n\n## Connect \u0026 Say 👋\n- **Follow** me on [👨‍💻 Github][github] and stay updated on free and open-source software\n- **Follow** me on [🐦 Twitter][twitter] to get updates on my latest open source projects\n- **Message** me on [📠 Telegram][telegram]\n- **Follow** my pet on [Instagram][sofythelabrador] for some _dog-tastic_ updates!\n\n---\n\n\u003cp align=\"center\"\u003e\n\u003ci\u003eBuilt With ♥ By \u003ca href=\"https://sva.onl/twitter\"  target=\"_blank\" rel=\"noopener noreferrer\"\u003eVarun Sridharan\u003c/a\u003e 🇮🇳 \u003c/i\u003e\n\u003c/p\u003e\n\n---\n\n\u003c!-- Personl Links --\u003e\n[paypal]: https://sva.onl/paypal\n[buymeacoffee]: https://sva.onl/buymeacoffee\n[sofythelabrador]: https://www.instagram.com/sofythelabrador/\n[github]: https://sva.onl/github/\n[twitter]: https://sva.onl/twitter/\n[telegram]: https://sva.onl/telegram/\n[email]: https://sva.onl/email\n[website]: https://sva.onl/website/\n[NPM]: https://npmjs.com\n","project_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fvarunsridharan%2Fjs-is","html_url":"https://awesome.ecosyste.ms/projects/github.com%2Fvarunsridharan%2Fjs-is","lists_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fvarunsridharan%2Fjs-is/lists"}