[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"me":3,"catalog:en:frontend\u002Freact-forms-suspense":4,"config":235},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":133,"samples":150},"frontend","Frontend","","react-forms-suspense","React Forms Suspense","en",75,2925,[14,15,16],"junior","mid","senior",[18,21,24,27,30,33,36,39,42,45,48,51,54,57,60,63,66,69,72,75,78,79,82,85,88,91,94,97,100,103,106,109,112,115,118,121,124,127,130],{"key":19,"name":20,"count":11},"accessibility","Accessibility",{"key":22,"name":23,"count":11},"angular-change-detection","Angular Change Detection",{"key":25,"name":26,"count":11},"angular-components-lifecycle","Angular Components Lifecycle",{"key":28,"name":29,"count":11},"angular-dependency-injection","Angular Dependency Injection",{"key":31,"name":32,"count":11},"angular-directives-pipes","Angular Directives 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Security",[134,138,141,144,147],{"key":135,"name":136,"count":137},"angular","Angular",450,{"key":139,"name":140,"count":137},"javascript","JavaScript",{"key":142,"name":143,"count":137},"react","React",{"key":145,"name":146,"count":137},"typescript","TypeScript",{"key":148,"name":149,"count":137},"vue","Vue",[151,169,182,196,209,222],{"id":152,"topic":9,"difficulty":153,"body":154,"options":155,"correct_key":163,"explanation":168},"019f5be4-0abe-7368-8511-2d5435771821",2,"```jsx\nfunction EmailField() {\n  return \u003Cinput type=\"email\" value=\"user@example.com\" \u002F>;\n}\n```\nWhat happens when a user tries to edit this field in the browser?",[156,159,162,165],{"key":157,"text":158},"a","It updates normally on every keystroke, but the parent component never re-renders because of it.",{"key":160,"text":161},"b","React throws a synchronous render error, and the whole component tree unmounts immediately.",{"key":163,"text":164},"c","The field behaves as read-only, and React logs a dev warning about a missing onChange handler.",{"key":166,"text":167},"d","React silently converts the field into an uncontrolled input the first time a key is pressed.","A `value` prop makes an input controlled by React, and there's no `onChange` to feed a new value back in, so React keeps pinning the displayed text to \"user@example.com\" no matter what is typed — the field is effectively read-only. React also logs: \"You provided a `value` prop to a form field without an `onChange` handler. This will render a read-only field.\" Fix by adding `onChange`, using `readOnly` explicitly, or switching to `defaultValue` for an uncontrolled field.",{"id":170,"topic":9,"difficulty":153,"body":171,"options":172,"correct_key":160,"explanation":181},"019f5be4-0abe-7d6f-b3e7-f045cc305b5f","```jsx\n\u003Cinput value={query} onChange={handleChange} \u002F>\n\u002F\u002F on a later render, query becomes undefined\n```\nWhat does React do when a controlled input's `value` prop goes from a defined string to `undefined`?",[173,175,177,179],{"key":157,"text":174},"It keeps the input controlled and silently treats `undefined` as an empty string, no warnings involved.",{"key":160,"text":176},"It switches the input to uncontrolled and logs a dev warning about changing from controlled to uncontrolled.",{"key":163,"text":178},"It throws immediately and stops rendering the whole application tree without any recovery.",{"key":166,"text":180},"It ignores the new `undefined` value entirely and keeps showing whatever string was there before, unchanged.","React logs: \"A component is changing a controlled input to be uncontrolled. This is likely caused by the value changing from a defined to undefined, which should not happen.\" From that point on, the DOM manages the field's value itself and React no longer drives it — a component must stay controlled or uncontrolled for its whole lifetime, never switch mid-way.",{"id":183,"topic":9,"difficulty":184,"body":185,"options":186,"correct_key":157,"explanation":195},"019f5be4-0abf-77ee-8f75-9bcb2eb3df8c",1,"In plain HTML, a text input's native `change` event typically fires only when the field loses focus after its value changed. Which statement about React's `onChange` prop on an `\u003Cinput>` is correct?",[187,189,191,193],{"key":157,"text":188},"It fires on every keystroke, because React's `onChange` corresponds to the browser's native `input` event.",{"key":160,"text":190},"It only fires once on blur, exactly matching the native `change` event's timing and behavior in plain HTML.",{"key":163,"text":192},"It fires exactly once, right after the component mounts, regardless of any typing.",{"key":166,"text":194},"It fires only when the user presses the Enter key while the field is focused.","React's `onChange` is intentionally named after the HTML attribute but wired to the native `input` event under the hood, so it fires on every keystroke (and on paste, cut, etc.) rather than waiting for blur like a native `change` listener would. This is why `onChange` is the standard way to keep controlled input state in sync as the user types.",{"id":197,"topic":9,"difficulty":153,"body":198,"options":199,"correct_key":166,"explanation":208},"019f5be4-0ac0-7379-a1f7-34462862ee04","```jsx\nfunction ProfileForm() {\n  const [form, setForm] = useState({ name: '', email: '' });\n\n  function handleChange(e) {\n    const { name, value } = e.target;\n    setForm(prev => ({ ...prev, [name]: value }));\n  }\n\n  return (\n    \u003C>\n      \u003Cinput name=\"name\" value={form.name} onChange={handleChange} \u002F>\n      \u003Cinput name=\"email\" value={form.email} onChange={handleChange} \u002F>\n    \u003C\u002F>\n  );\n}\n```\nWhy does this pattern let one `handleChange` function drive both inputs correctly?",[200,202,204,206],{"key":157,"text":201},"React automatically merges any two sibling inputs sharing the same handler into a single state field.",{"key":160,"text":203},"The `name` attribute is only used for accessibility labels; the real routing comes from input order.",{"key":163,"text":205},"`e.target.value` returns an array of both inputs' values, which `setForm` then splits by position.",{"key":166,"text":207},"`e.target.name` identifies which input fired the event, so `[name]: value` updates only that one key.","`e.target` is the DOM input that triggered the change, so `e.target.name` reads back the `name` attribute of that specific field. Using it as a computed property key (`[name]: value`) inside the spread lets a single handler update exactly the matching key in the form object while leaving the rest of the state untouched.",{"id":210,"topic":9,"difficulty":184,"body":211,"options":212,"correct_key":160,"explanation":221},"019f5be4-0ac0-7d86-9d61-0d94e8fb6570","```jsx\nfunction SearchForm({ onSearch }) {\n  function handleSubmit(e) {\n    onSearch();\n  }\n  return (\n    \u003Cform onSubmit={handleSubmit}>\n      \u003Cbutton type=\"submit\">Search\u003C\u002Fbutton>\n    \u003C\u002Fform>\n  );\n}\n```\nClicking the button triggers a full page reload before `onSearch` seems to take effect. What is missing from `handleSubmit`?",[213,215,217,219],{"key":157,"text":214},"The button needs `type=\"button\"` instead of `type=\"submit\"` so the form doesn't submit at all.",{"key":160,"text":216},"`e.preventDefault()` is missing, so the browser performs its default form submission and navigates.",{"key":163,"text":218},"`handleSubmit` needs to be declared as `async` for React to intercept the form's submit event.",{"key":166,"text":220},"The `\u003Cform>` element needs an explicit `action=\"#\"` attribute to stay on the same page.","A native `\u003Cform>` submits and reloads the page by default when a submit button is clicked, unless something cancels that behavior. Calling `e.preventDefault()` inside the `onSubmit` handler stops the browser's default navigation, letting `onSearch()` run as the only visible effect.",{"id":223,"topic":9,"difficulty":153,"body":224,"options":225,"correct_key":163,"explanation":234},"019f5be4-0ac1-75f1-8621-f5414bbf42bf","```jsx\nfunction TermsCheckbox() {\n  const [accepted, setAccepted] = useState(false);\n  return (\n    \u003Cinput\n      type=\"checkbox\"\n      checked={accepted}\n      onChange={e => setAccepted(e.target.value)}\n    \u002F>\n  );\n}\n```\nAfter the first click the box stays checked and can never be unchecked. What is the bug?",[226,228,230,232],{"key":157,"text":227},"`useState(false)` is invalid for a checkbox; it must be initialized with an empty string instead.",{"key":160,"text":229},"Checkboxes cannot be controlled components in React and must always be left uncontrolled.",{"key":163,"text":231},"A checkbox's controlled state is bound with `checked`\u002F`e.target.checked`, not `value`\u002F`e.target.value`.",{"key":166,"text":233},"The `onChange` handler must always be renamed to `onClick` for checkbox and radio input types specifically.","A checkbox is controlled with the boolean `checked` prop and read back from `e.target.checked`. Here the handler reads `e.target.value`, which for a checkbox is the fixed submit string (`\"on\"` by default) — so after the first click `accepted` becomes the truthy string `\"on\"` and `checked={accepted}` stays true forever (verified by running it). Reading `e.target.checked` gives the boolean React actually needs.",{"fields":236,"seniorities":410,"interview_shapes":411,"locales":416,"oauth":418,"question_count":421,"coach_enabled":422,"jd_match_enabled":422},[237,262,270,287,311,324,343,362,384,391,397,404],{"key":238,"name_tr":239,"name_en":239,"sort":184,"specializations":240},"backend","Backend",[241,244,247,250,253,256,259],{"key":242,"name":243,"field":238},"general","Genel",{"key":245,"name":246,"field":238},"go","Go",{"key":248,"name":249,"field":238},"python","Python",{"key":251,"name":252,"field":238},"java","Java",{"key":254,"name":255,"field":238},"csharp","C#\u002F.NET",{"key":257,"name":258,"field":238},"nodejs","Node.js",{"key":260,"name":261,"field":238},"php","PHP",{"key":5,"name_tr":6,"name_en":6,"sort":153,"specializations":263},[264,265,266,267,268,269],{"key":242,"name":243,"field":5},{"key":139,"name":140,"field":5},{"key":145,"name":146,"field":5},{"key":142,"name":143,"field":5},{"key":148,"name":149,"field":5},{"key":135,"name":136,"field":5},{"key":271,"name_tr":272,"name_en":272,"sort":273,"specializations":274},"fullstack","Fullstack",3,[275,276,277,278,279,280,281,282,283,284,285,286],{"key":242,"name":243,"field":271},{"key":245,"name":246,"field":238},{"key":248,"name":249,"field":238},{"key":251,"name":252,"field":238},{"key":254,"name":255,"field":238},{"key":257,"name":258,"field":238},{"key":260,"name":261,"field":238},{"key":139,"name":140,"field":5},{"key":145,"name":146,"field":5},{"key":142,"name":143,"field":5},{"key":148,"name":149,"field":5},{"key":135,"name":136,"field":5},{"key":288,"name_tr":289,"name_en":289,"sort":290,"specializations":291},"devops-cloud","DevOps \u002F Cloud",4,[292,293,296,299,302,305,308],{"key":242,"name":243,"field":288},{"key":294,"name":295,"field":288},"aws","AWS",{"key":297,"name":298,"field":288},"gcp","GCP",{"key":300,"name":301,"field":288},"azure","Azure",{"key":303,"name":304,"field":288},"kubernetes","Kubernetes",{"key":306,"name":307,"field":288},"terraform","Terraform",{"key":309,"name":310,"field":288},"linux","Linux",{"key":312,"name_tr":313,"name_en":313,"sort":314,"specializations":315},"ai-engineer","AI Engineer",5,[316,317,318,321],{"key":242,"name":243,"field":312},{"key":248,"name":249,"field":312},{"key":319,"name":320,"field":312},"llm-rag","LLM\u002FRAG",{"key":322,"name":323,"field":312},"mlops","MLOps",{"key":325,"name_tr":326,"name_en":327,"sort":328,"specializations":329},"database","Veritabanı","Database",6,[330,331,334,337,340],{"key":242,"name":243,"field":325},{"key":332,"name":333,"field":325},"postgresql","PostgreSQL",{"key":335,"name":336,"field":325},"mysql","MySQL",{"key":338,"name":339,"field":325},"mongodb","MongoDB",{"key":341,"name":342,"field":325},"redis","Redis",{"key":344,"name_tr":345,"name_en":346,"sort":347,"specializations":348},"mobile","Mobil","Mobile",7,[349,350,353,356,359],{"key":242,"name":243,"field":344},{"key":351,"name":352,"field":344},"ios-swift","iOS (Swift)",{"key":354,"name":355,"field":344},"android-kotlin","Android (Kotlin)",{"key":357,"name":358,"field":344},"flutter","Flutter",{"key":360,"name":361,"field":344},"react-native","React Native",{"key":363,"name_tr":364,"name_en":365,"sort":366,"specializations":367},"security","Güvenlik","Security",8,[368,369,372,375,378,381],{"key":242,"name":243,"field":363},{"key":370,"name":371,"field":363},"appsec","AppSec",{"key":373,"name":374,"field":363},"offensive-pentest","Offensive \u002F Pentest",{"key":376,"name":377,"field":363},"cloud-security","Cloud Security",{"key":379,"name":380,"field":363},"devsecops","DevSecOps",{"key":382,"name":383,"field":363},"blue-team-incident","Blue Team \u002F Incident",{"key":385,"name_tr":386,"name_en":387,"sort":388,"specializations":389},"qa-test-automation","QA \u002F Test Otomasyonu","QA \u002F Test Automation",9,[390],{"key":242,"name":243,"field":385},{"key":392,"name_tr":393,"name_en":393,"sort":394,"specializations":395},"data-engineer","Data Engineer",10,[396],{"key":242,"name":243,"field":392},{"key":398,"name_tr":399,"name_en":400,"sort":401,"specializations":402},"game-dev","Oyun Geliştirme","Game Development",11,[403],{"key":242,"name":243,"field":398},{"key":405,"name_tr":406,"name_en":406,"sort":407,"specializations":408},"ml-engineer","ML Engineer",12,[409],{"key":242,"name":243,"field":405},[14,15,16],{"junior":412,"mid":414,"senior":415},{"questions":413,"median_sec":3},20,{"questions":413,"median_sec":3},{"questions":413,"median_sec":3},[417,10],"tr",[419,420],"google","github",21750,true]