--- title: QA Learning Journal #3: Understanding Data Types & Operators description: A beginner QA engineer's learning journal entry covering JavaScript fundamentals needed for Playwright automation. Topics include primitive data types (String,... canonical: https://daily.dev/posts/qa-learning-journal-3-understanding-data-types-operators-onypjnbfl twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: QA Learning Journal #3: Understanding Data Types & Operators | daily.dev og:description: A beginner QA engineer's learning journal entry covering JavaScript fundamentals needed for Playwright automation. Topics include primitive data types (String,... og:url: https://daily.dev/posts/qa-learning-journal-3-understanding-data-types-operators-onypjnbfl og:image: https://api.daily.dev/og/posts/OnYPJNbFl.png og:image:alt: QA Learning Journal #3: Understanding Data Types & Operators og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # QA Learning Journal #3: Understanding Data Types & Operators **[Medium](https://daily.dev/sources/medium_js)** · 3 min read · 0 upvotes · 0 comments ## Summary A beginner QA engineer's learning journal entry covering JavaScript fundamentals needed for Playwright automation. Topics include primitive data types (String, Number, Boolean, Undefined, Null, BigInt, Symbol), the typeof operator for type checking, and the four main operator categories: arithmetic, comparison, assignment, and logical operators. Written from a QA perspective with automation testing as the motivating context. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Similar posts on daily.dev - [Dynamic Data: A Beginner’s Guide to JavaScript Data Type](https://daily.dev/posts/dynamic-data-a-beginner-s-guide-to-javascript-data-type-zy1zgrsrx) · Medium · 3 upvotes · 0 comments - [The Basics of JavaScript](https://daily.dev/posts/the-basics-of-javascript-vp6w47za7) · Medium · 2 upvotes · 0 comments - [Visual Types](https://daily.dev/posts/visual-types-yqneyg40x) · Lobsters · 5 upvotes · 0 comments --- Tags: [#javascript](https://daily.dev/tags/javascript), [#testing](https://daily.dev/tags/testing) [View this post on daily.dev](https://daily.dev/posts/qa-learning-journal-3-understanding-data-types-operators-onypjnbfl) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"QA Learning Journal #3: Understanding Data Types & Operators","url":"https://daily.dev/posts/qa-learning-journal-3-understanding-data-types-operators-onypjnbfl","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/qa-learning-journal-3-understanding-data-types-operators-onypjnbfl"},"datePublished":"2026-07-26T11:11:48.701Z","dateModified":"2026-09-14T08:46:14.259Z","description":"A beginner QA engineer's learning journal entry covering JavaScript fundamentals needed for Playwright automation. 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