[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"me":3,"catalog:en:mobile\u002Frn-javascript-typescript-fundamentals":4,"config":211},null,{"field_key":5,"field_name":6,"seniority":7,"topic_key":8,"topic_name":9,"spec_key":7,"spec_name":7,"locale":10,"cell_total":11,"field_total":12,"seniorities":13,"topics":17,"specs":112,"samples":126},"mobile","Mobile","","rn-javascript-typescript-fundamentals","Rn Javascript Typescript Fundamentals","en",75,2400,[14,15,16],"junior","mid","senior",[18,21,24,27,30,33,36,39,42,45,48,51,54,57,60,63,66,69,72,75,78,81,84,87,90,93,96,97,100,103,106,109],{"key":19,"name":20,"count":11},"fl-dart-async-isolates","Fl Dart Async Isolates",{"key":22,"name":23,"count":11},"fl-dart-language-null-safety","Fl Dart Language Null Safety",{"key":25,"name":26,"count":11},"fl-flutter-persistence-storage","Fl Flutter Persistence Storage",{"key":28,"name":29,"count":11},"fl-flutter-platform-channels-lifecycle","Fl Flutter Platform Channels Lifecycle",{"key":31,"name":32,"count":11},"fl-flutter-rendering-widget-tree","Fl Flutter Rendering Widget Tree",{"key":34,"name":35,"count":11},"fl-flutter-state-management-widgets","Fl Flutter State Management Widgets",{"key":37,"name":38,"count":11},"ios-core-data-swiftdata-persistence","Ios Core Data Swiftdata Persistence",{"key":40,"name":41,"count":11},"ios-lifecycle-background-execution","Ios Lifecycle Background Execution",{"key":43,"name":44,"count":11},"ios-memory-management-arc","Ios Memory Management Arc",{"key":46,"name":47,"count":11},"ios-swift-concurrency-structured","Ios Swift Concurrency Structured",{"key":49,"name":50,"count":11},"ios-swift-type-system-optionals","Ios Swift Type System Optionals",{"key":52,"name":53,"count":11},"ios-swiftui-state-rendering","Ios Swiftui State Rendering",{"key":55,"name":56,"count":11},"kt-android-lifecycle-background-execution","Kt Android Lifecycle Background Execution",{"key":58,"name":59,"count":11},"kt-android-memory-context-leaks","Kt Android Memory Context Leaks",{"key":61,"name":62,"count":11},"kt-android-room-persistence","Kt Android Room Persistence",{"key":64,"name":65,"count":11},"kt-jetpack-compose-state-recomposition","Kt Jetpack Compose State Recomposition",{"key":67,"name":68,"count":11},"kt-kotlin-coroutines-flow","Kt Kotlin Coroutines Flow",{"key":70,"name":71,"count":11},"kt-kotlin-type-system-null-safety","Kt Kotlin Type System Null Safety",{"key":73,"name":74,"count":11},"mobile-distribution-ci","Mobile Distribution Ci",{"key":76,"name":77,"count":11},"mobile-navigation","Mobile Navigation",{"key":79,"name":80,"count":11},"mobile-networking-offline","Mobile Networking Offline",{"key":82,"name":83,"count":11},"mobile-performance-battery","Mobile Performance Battery",{"key":85,"name":86,"count":11},"mobile-security-storage","Mobile Security Storage",{"key":88,"name":89,"count":11},"mobile-state-data","Mobile State Data",{"key":91,"name":92,"count":11},"mobile-testing-automation","Mobile Testing Automation",{"key":94,"name":95,"count":11},"mobile-ui-lifecycle","Mobile Ui Lifecycle",{"key":8,"name":9,"count":11},{"key":98,"name":99,"count":11},"rn-native-bridge-modules","Rn Native Bridge Modules",{"key":101,"name":102,"count":11},"rn-navigation-lifecycle","Rn Navigation Lifecycle",{"key":104,"name":105,"count":11},"rn-networking-persistence-offline","Rn Networking Persistence Offline",{"key":107,"name":108,"count":11},"rn-performance-rendering","Rn Performance Rendering",{"key":110,"name":111,"count":11},"rn-react-hooks-state-management","Rn React Hooks State Management",[113,117,120,123],{"key":114,"name":115,"count":116},"android-kotlin","Android (Kotlin)",450,{"key":118,"name":119,"count":116},"flutter","Flutter",{"key":121,"name":122,"count":116},"ios-swift","iOS (Swift)",{"key":124,"name":125,"count":116},"react-native","React Native",[127,145,159,172,185,198],{"id":128,"topic":9,"difficulty":129,"body":130,"options":131,"correct_key":139,"explanation":144},"019fa9e5-71bb-71b9-acc1-76d6acac3a59",1,"In a React Native screen component, what is a closure?",[132,135,138,141],{"key":133,"text":134},"a","A function that automatically runs when the component unmounts.",{"key":136,"text":137},"b","A copy of a component's props that never changes after the first render.",{"key":139,"text":140},"c","A function that retains access to variables from the scope it was defined in, even after that scope has finished executing.",{"key":142,"text":143},"d","A special React Native API for closing native modules after use.","A closure is a function bundled together with references to its surrounding lexical scope. In RN this is why, for example, a callback passed to a `Button onPress` can still read a variable declared in the component function body.",{"id":146,"topic":9,"difficulty":147,"body":148,"options":149,"correct_key":136,"explanation":158},"019fa9e5-71c3-7358-863c-202686d1dde7",2,"```js\nconst user = {\n  name: 'Ada',\n  greet: function () {\n    return `Hi, ${this.name}`;\n  },\n};\nconst fn = user.greet;\nfn();\n```\nWhat does calling `fn()` return (in a React Native\u002FHermes JS environment, non-strict interop aside, `this` is undefined)?",[150,152,154,156],{"key":133,"text":151},"`\"Hi, Ada\"`, because `this` in a regular function always refers to the object it was originally defined on.",{"key":136,"text":153},"It throws, because `this` is `undefined` inside `fn` and `this.name` fails.",{"key":139,"text":155},"`\"Hi, undefined\"`, because `this` becomes the global object and `name` is not a global variable.",{"key":142,"text":157},"It returns `\"Hi, \"` with an empty string, because Hermes defaults unresolved `this` properties to empty string.","Regular functions get `this` from how they are called, not where they are defined. Assigning `user.greet` to `fn` and calling `fn()` calls it as a plain function, so `this` is `undefined` in Hermes\u002Fstrict ES module code, and accessing `this.name` throws a TypeError.",{"id":160,"topic":9,"difficulty":147,"body":161,"options":162,"correct_key":133,"explanation":171},"019fa9e5-71c5-71ed-a543-354c7540157f","```js\nconsole.log('start');\nsetTimeout(() => console.log('timeout'), 0);\nPromise.resolve().then(() => console.log('promise'));\nconsole.log('end');\n```\nWhat is the logged order?",[163,165,167,169],{"key":133,"text":164},"start, end, promise, timeout",{"key":136,"text":166},"start, end, timeout, promise",{"key":139,"text":168},"start, promise, timeout, end — because promises always run before synchronous code finishes.",{"key":142,"text":170},"start, timeout, promise, end","Synchronous code runs first (`start`, `end`). Then the microtask queue (Promise callbacks) drains before the macrotask queue (`setTimeout` callbacks), so `promise` logs before `timeout`.",{"id":173,"topic":9,"difficulty":129,"body":174,"options":175,"correct_key":136,"explanation":184},"019fa9e5-71c6-71ad-b79a-12d42e448c43","When you write `const arr = [1, 2, 3]; arr.map(x => x * 2)`, how does `arr.map` get resolved if `Array.prototype` doesn't directly define `map` on `arr` itself?",[176,178,180,182],{"key":133,"text":177},"It doesn't resolve; `map` must be manually copied onto every array instance by the JS engine at creation time.",{"key":136,"text":179},"The engine walks up the prototype chain from `arr` to `Array.prototype`, where `map` is found and used.",{"key":139,"text":181},"React Native's Hermes engine injects `map` globally onto every variable regardless of type.",{"key":142,"text":183},"TypeScript's compiler inlines `map`'s implementation directly into the compiled JS at build time.","JS objects (arrays included) have an internal `[[Prototype]]` link. Property\u002Fmethod lookup walks this chain until it finds the property or reaches `null`. `arr`'s prototype is `Array.prototype`, which defines `map`.",{"id":186,"topic":9,"difficulty":147,"body":187,"options":188,"correct_key":142,"explanation":197},"019fa9e5-71c7-7111-8410-ae0e8bddb059","```ts\nfunction wrapInArray\u003CT>(value: T): T[] {\n  return [value];\n}\nconst result = wrapInArray(42);\n```\nWhat is the inferred type of `result`?",[189,191,193,195],{"key":133,"text":190},"`any[]`, because TypeScript cannot infer generic types from function arguments.",{"key":136,"text":192},"`T[]`, literally, since `T` stays a placeholder until a type annotation is added.",{"key":139,"text":194},"`unknown[]`, because generics default to `unknown` when the call site provides a primitive.",{"key":142,"text":196},"`number[]`, because TypeScript infers `T` as `number` from the argument `42`.","TypeScript performs generic type inference from the call arguments: passing `42` makes `T` resolve to `number`, so the return type `T[]` becomes `number[]`.",{"id":199,"topic":9,"difficulty":147,"body":200,"options":201,"correct_key":142,"explanation":210},"019fa9e5-71ca-7074-9d84-cbd6bc0c50cf","```js\nasync function loadProfile() {\n  const res = await fetch('\u002Fapi\u002Fprofile');\n  const data = await res.json();\n  return data.name;\n}\n```\nWhat does calling `loadProfile()` actually return?",[202,204,206,208],{"key":133,"text":203},"The string value of `data.name` directly, synchronously.",{"key":136,"text":205},"`undefined`, because `async` functions cannot return values, only side effects.",{"key":139,"text":207},"A `fetch` response object wrapping `data.name`.",{"key":142,"text":209},"A `Promise` that resolves to the value of `data.name`.","An `async` function always returns a `Promise`, regardless of what its body `return`s. Callers need `await loadProfile()` or `.then(...)` to access the resolved `name` value.",{"fields":212,"seniorities":388,"interview_shapes":389,"locales":394,"oauth":396,"question_count":399,"coach_enabled":400,"jd_match_enabled":400},[213,238,258,275,299,312,331,340,362,369,375,382],{"key":214,"name_tr":215,"name_en":215,"sort":129,"specializations":216},"backend","Backend",[217,220,223,226,229,232,235],{"key":218,"name":219,"field":214},"general","Genel",{"key":221,"name":222,"field":214},"go","Go",{"key":224,"name":225,"field":214},"python","Python",{"key":227,"name":228,"field":214},"java","Java",{"key":230,"name":231,"field":214},"csharp","C#\u002F.NET",{"key":233,"name":234,"field":214},"nodejs","Node.js",{"key":236,"name":237,"field":214},"php","PHP",{"key":239,"name_tr":240,"name_en":240,"sort":147,"specializations":241},"frontend","Frontend",[242,243,246,249,252,255],{"key":218,"name":219,"field":239},{"key":244,"name":245,"field":239},"javascript","JavaScript",{"key":247,"name":248,"field":239},"typescript","TypeScript",{"key":250,"name":251,"field":239},"react","React",{"key":253,"name":254,"field":239},"vue","Vue",{"key":256,"name":257,"field":239},"angular","Angular",{"key":259,"name_tr":260,"name_en":260,"sort":261,"specializations":262},"fullstack","Fullstack",3,[263,264,265,266,267,268,269,270,271,272,273,274],{"key":218,"name":219,"field":259},{"key":221,"name":222,"field":214},{"key":224,"name":225,"field":214},{"key":227,"name":228,"field":214},{"key":230,"name":231,"field":214},{"key":233,"name":234,"field":214},{"key":236,"name":237,"field":214},{"key":244,"name":245,"field":239},{"key":247,"name":248,"field":239},{"key":250,"name":251,"field":239},{"key":253,"name":254,"field":239},{"key":256,"name":257,"field":239},{"key":276,"name_tr":277,"name_en":277,"sort":278,"specializations":279},"devops-cloud","DevOps \u002F Cloud",4,[280,281,284,287,290,293,296],{"key":218,"name":219,"field":276},{"key":282,"name":283,"field":276},"aws","AWS",{"key":285,"name":286,"field":276},"gcp","GCP",{"key":288,"name":289,"field":276},"azure","Azure",{"key":291,"name":292,"field":276},"kubernetes","Kubernetes",{"key":294,"name":295,"field":276},"terraform","Terraform",{"key":297,"name":298,"field":276},"linux","Linux",{"key":300,"name_tr":301,"name_en":301,"sort":302,"specializations":303},"ai-engineer","AI Engineer",5,[304,305,306,309],{"key":218,"name":219,"field":300},{"key":224,"name":225,"field":300},{"key":307,"name":308,"field":300},"llm-rag","LLM\u002FRAG",{"key":310,"name":311,"field":300},"mlops","MLOps",{"key":313,"name_tr":314,"name_en":315,"sort":316,"specializations":317},"database","Veritabanı","Database",6,[318,319,322,325,328],{"key":218,"name":219,"field":313},{"key":320,"name":321,"field":313},"postgresql","PostgreSQL",{"key":323,"name":324,"field":313},"mysql","MySQL",{"key":326,"name":327,"field":313},"mongodb","MongoDB",{"key":329,"name":330,"field":313},"redis","Redis",{"key":5,"name_tr":332,"name_en":6,"sort":333,"specializations":334},"Mobil",7,[335,336,337,338,339],{"key":218,"name":219,"field":5},{"key":121,"name":122,"field":5},{"key":114,"name":115,"field":5},{"key":118,"name":119,"field":5},{"key":124,"name":125,"field":5},{"key":341,"name_tr":342,"name_en":343,"sort":344,"specializations":345},"security","Güvenlik","Security",8,[346,347,350,353,356,359],{"key":218,"name":219,"field":341},{"key":348,"name":349,"field":341},"appsec","AppSec",{"key":351,"name":352,"field":341},"offensive-pentest","Offensive \u002F Pentest",{"key":354,"name":355,"field":341},"cloud-security","Cloud Security",{"key":357,"name":358,"field":341},"devsecops","DevSecOps",{"key":360,"name":361,"field":341},"blue-team-incident","Blue Team \u002F Incident",{"key":363,"name_tr":364,"name_en":365,"sort":366,"specializations":367},"qa-test-automation","QA \u002F Test Otomasyonu","QA \u002F Test Automation",9,[368],{"key":218,"name":219,"field":363},{"key":370,"name_tr":371,"name_en":371,"sort":372,"specializations":373},"data-engineer","Data Engineer",10,[374],{"key":218,"name":219,"field":370},{"key":376,"name_tr":377,"name_en":378,"sort":379,"specializations":380},"game-dev","Oyun Geliştirme","Game Development",11,[381],{"key":218,"name":219,"field":376},{"key":383,"name_tr":384,"name_en":384,"sort":385,"specializations":386},"ml-engineer","ML Engineer",12,[387],{"key":218,"name":219,"field":383},[14,15,16],{"junior":390,"mid":392,"senior":393},{"questions":391,"median_sec":3},20,{"questions":391,"median_sec":3},{"questions":391,"median_sec":3},[395,10],"tr",[397,398],"google","github",21750,true]