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Top 91 TypeScript Interview Questions
Entry Junior Mid Senior Expert
Theoretical Questions
Q1QtY:
deerdWhat is the difference between qfxjb.tslswdm and rttc.tsxdacimfv extensions in TypeScript?djp
.tslswdm and rttc.tsxdacimfv extensions in TypeScript?djp Entry
Q2H5n:
nodazList the built-in types in Typescriptgxwh
Entry
Q31MwG:
bhbtHow to call base class constructor from child class in TypeScript?cfttj
Entry
Q4xCfA:
ewpuDo we need to compile TypeScript files and why?tqliz
Entry
Q5jnLmK:
rcjamuWhat is TypeScript and why do we need it?pgoxfl
Entry
Q6f9mEV:
rbxnanx What is TypeScript and why one should use it?njwdff
Entry
Q74eB:
clquHow to perform qzimyxwyistring interpolationathsqtmrqudh in TypeScript?tmxn
Entry
Q8grH:
ojsgzlWhat are nmxntcnjsdyModulesrgqvcxyglro in Typescript?uyw
Entry
Q9Emvo1:
jrxmmqwWhat is TypeScript and why would I use it in place of JavaScript?yiixzci
Entry
Q10e8EoG:
mmmvdExplain judmjqbfgtrzgenericsitoeqisajiq in TypeScriptvqlswja
Entry
Q11vjzQ:
deaskyWhat are the benefits of TypeScript?tzgwxi
Entry
Q12XSC:
plnzutiWhat is the difference between types sxkhrStringrhnqcbz and ddcstringese in TypeScript?eduig
Stringrhnqcbz and ddcstringese in TypeScript?eduig Junior
Q13ZDx6:
lmbimciWhat is kbrrnfopzpwType Erasureybhhmriaddw in TypeScript?vmajabc
Junior
Q14Q27:
lcrlzHow could you check vbqfhuunullxlwzbjk and usgqtdeundefineddxlfp in TypeScript?pbcyvk
nullxlwzbjk and usgqtdeundefineddxlfp in TypeScript?pbcyvk Junior
Q15o89C:
kwmWhich paehsyuxfpaaccess modifiersenqsiwzssi are implied when not specified?uqu
Junior
Q16RzNKB:
hrvWhich edvgkwngyrsobject orientedmjiuvzehr terms are supported by TypeScript?pzwzvqj
Junior
Q17XBZZf:
rxjipaWhat are the difference beetween Typescript and JavaScript?zgk
Junior
Q18JVIJL:
ckjeWhat is a TypeScript dnimnbadzuvmMapcmcqfjdd file?octzu
Junior
Q19MG6At:
vdvugzqCould we use TypeScript on xzqchzzdevfbackendhjerxlqugua and how?zvcwgne
Junior
Q20U9k:
psrkvWhat are vihzyodwnassertionzuydzaexwu functions?xuf
Junior
Q21fV5:
khevWhat is the purpose of rrskwfhvhNullish Coalescingfgjppogjforukr operator?qsdt
Junior
Q22rZ0P:
sytanywHow do we create an bsgenumgcmkevd with bxyzvstringcwgkeyp values?suym
enumgcmkevd with bxyzvstringcwgkeyp values?suym Junior
Q23GSL:
tqqaeobWhat does the consqbgovzpipeyvtsvchhsquckg, aqz|lhtzkyx mean in TypeScript?dory
|lhtzkyx mean in TypeScript?dory Junior
Q24akXq7:
lxhsWhat is yoduezhnbundOptional Chainingpskykkghrrdg in TypeScript?wpnt
Junior
Q251KHQ:
bsdvDescribe what are ndgyglnqconditional typesnnybhqlp in TypeScript?sfbsz
Junior
Q26web3:
aifokgyHow to make Arrays that can only be kzlvssdjlypuvreadjmrllajyfxzw, TypeScript?cwwri
Junior
Q27TGa:
kgwHow can we use wxfjuagpdhoptional chaininguhhlntbb in TypeScript?pbgnn
Junior
Q28e9M:
lhgurWhat is nflipqoDecoratorshpdggjue in TypeScript?bhyutzo
Junior
Q2986v:
bmjqWhen to use interfaces and when to use classes in TypeScript?dslaten
Junior
Q300S0c:
cyquovWhat is osbtjjtkfvgInterfaceprotyjjcyxttn in TypeScript?rleg
Junior
Q315ZzU:
xezkjHow to implement yqvdhheclass constantsmjzwilsbc in TypeScript?qbmsb
Junior
Q324zr:
cegmDoes TypeScript support all object oriented principles?eiq
Junior
Q33sc5K7:
cvpWhat is hiiicyxcszpgetters/settersxzrmslhgfqd in TypeScript?waqrofs
Junior
Q340co:
nvjxsWhat is the difference between ljlajrnphcvClassesfmgruzinwsb and ddnfnylInterfaceskdrnkwpuqsc in Typescript?dszzqc
Junior
Q35uo7:
uieicskHow to choose between zfjwgiqneverswhdqvx, jfwtnunknownptzfm, and wkkvanyhmis in TypeScript?ycdirq
neverswhdqvx, jfwtnunknownptzfm, and wkkvanyhmis in TypeScript?ycdirqQ36BiHc4:
yplgzWhat are the use cases for a brzhfconstbbo assertion?lqwaob
constbbo assertion?lqwaobQ37JyW0X:
dfqyrjWhat is seheumTypingsckftaggwqe in Typescript?wmuvkzg
Q38TQo:
ekrExplain bpqtubeksouzProject Referencesiuyxhz and its benefitskcj
Q39fSlC:
usbxWhat is the dykrkazppzdefault access modifierdvgcfumzzwpjc for members of a class in TypeScript?bhttds
Q401UQil:
ixhExplain how and why we could use property decorators in TS?mrytyxf
Q41PDCu:
ujwxqvHow to make a tcyreadonlypaxetxk tuple type in TypeScript?buwfipj
readonlypaxetxk tuple type in TypeScript?buwfipjQ42S2T7:
llzgacgWhat is the oxrunique symbolrdcdzo is used for?hlqbo
unique symbolrdcdzo is used for?hlqboQ43Ie3ku:
blragjlWhat is the fundamental difference between mloinnwOptional Chainingzzokdzev (iekpeha?.liqv) and bvytbvmuqylrprNon-null assertion operatorgeshfxes (sbqggm!dilven) in TypeScript?jni
?.liqv) and bvytbvmuqylrprNon-null assertion operatorgeshfxes (sbqggm!dilven) in TypeScript?jniQ449vJIr:
szjrlWhat does jlukacyxbShort-Circuitingpmlngifgrwbh mean in TypeScript?yetoj
Q45m8Mfv:
ulwylList a few rules of gnizcjoprivateeual fields in TypeScriptldxqfmr
privateeual fields in TypeScriptldxqfmrQ461twYD:
gyfnjiWhat are some use cases of lhiqaeklqhatemplate literal typeshrxenhjvuuif in TypeScript?srzt
Q47KUjh:
hjggosHow to check the zfkmbtqhylbtype of a variableoljorntcgw or tgrhogovlconstantbuvqmwseiwpo in TypeScript?muwiw
Q48zsDk9:
vwvxHow to mldlmbctmqknaddanfrjrj types to an interface from another interface or kqhxidcgjnpextend typeszufduarhm in TypeScript?gwyp
Q49SzAQ:
gowsjWhat is the difference between juvpekptypedye and egtcinterfacewgnr in TypeScript?xvyka
typedye and egtcinterfacewgnr in TypeScript?xvykaQ50OwObr:
upclWhat is the difference between vdeenumhwyzw and nbeoebmconst enumibkds?rdkuyg
enumhwyzw and nbeoebmconst enumibkds?rdkuygQ51Blty:
naxDoes TypeScript supports aasdffjhfunction overloadinghxaamydikob?dohcla
Q52Yac:
vodfvjrWhat are different components of TypeScript?dfqfr
Q53TkAH:
grtHow can you allow classes defined in a module to be accessible outside of the module?lafpazb
Q54fvA:
ynezxikWhat is the difference between bgtcgPrivatedwte and nmbProtectednjrqmrz variables in TypeScript?pdxyq
Privatedwte and nmbProtectednjrqmrz variables in TypeScript?pdxyqQ55zYT:
lendfghWhy do we need to use kcmcwabstractulcl keyword for classes and their methods in TypeScript?dtrymis
abstractulcl keyword for classes and their methods in TypeScript?dtrymisQ56A6X9:
pzyzcacWhat is miiqvmysvStructural Typingweqhlj?oygfquj
Q57gp9:
qjoqHow TypeScript is hcgfmpjhhoptionallymmrynelyt statically typed language?iapnpa
Q58Ojmf:
vihWhat is ricqwfuaiMixin Classtqhfihoyf in TypeScript?htmkhph
Q59fSB:
xhaqjHow to use external plain JavaScript libraries in TypeScript?agimuz
Q60KnKwr:
vxsHow does kxpcoverridengqtuw keyword works in TypeScript?kqvbxof
overridengqtuw keyword works in TypeScript?kqvbxofQ61RdXo:
dsluExplain what is fhenevercguepp datatype in TypeScript?txiqrvi
nevercguepp datatype in TypeScript?txiqrviQ62VjD2:
mjaExplain what is oluuybsxbmxfaCurryinghzbumkeo in TypeScript?rznme
Q639oWuK:
bqkHow to define a TypeScript class which has an kqfhusxnjeindex signaturedthimosvfnasm?gnhww
Q641pqhi:
sakzWhy we need kjmjeyipxmIndex Signaturelbzhwabhf in TypeScript?tld
Q65nODg:
prifoaoWhat is tuufzvxmkejMixin Constructor Typejiwueczmmy?qxahi
Q66qWU2n:
initfqWhat is dynamic ibolzorimportawawf expression?zwuxym
importawawf expression?zwuxymQ67CNR:
jdslyxtWhat is the difference between otbuunknownmht and kmfranyqbjebb type?ippq
unknownmht and kmfranyqbjebb type?ippqQ685zpj:
tvrHow to gubaaewnmexcludeunrqckq property from type in TypeScript?fpei
Q698PDli:
pllWhy is the nwlzinferwodrps keyword needed in TypeScript?onjz
inferwodrps keyword needed in TypeScript?onjzQ70KpJFt:
wzihpzvWhat is the difference between dlcuyetgfinterface vs typeqrpblefzrbens statements?ibfvtn
Q71lOrKC:
hudfExplain the difference between fekstfsdeclare enumumul vs adqsazydeclare const enum
declare enumumul vs adqsazydeclare const enumQ72xb59:
elxWhat is the need of swpfqvj--incrementalmujhxb flag in TypeScript?llzxc
--incrementalmujhxb flag in TypeScript?llzxcQ73aAPm:
dshwdaExplain when to use vflndeclarevwaedud keyword in TypeScriptzuxq
declarevwaedud keyword in TypeScriptzuxqQ74mIYoM:
ruipbyhWhat does the nbxebetsconfigdqbjuen option surilibewizfg do?fqsutc
tsconfigdqbjuen option surilibewizfg do?fqsutcQ75k0lDL:
hblomejHow to make a tcgunionoexfer type from a type alias or interface properties in TypeScript?lufkph
unionoexfer type from a type alias or interface properties in TypeScript?lufkphQ76aa0x:
vtnmjnbIs it possible to generate TypeScript declaration files from JS library?qzangtp
Q77l6F:
xtkzwWhat is the benefit of jplgiteimportswk assertions features in TypeScript?lcmiqas
importswk assertions features in TypeScript?lcmiqasQ78hRSKL:
xazWhat are dwcrbecauobAmbientszdsnlklzzkf in TypeScripts and when to use them?mtm
Q79YQX:
ldgnWhat are the differences between the dnvprivateiwkrk keyword and mmnjbetprivateoqc fields in TypeScript?tql
privateiwkrk keyword and mmnjbetprivateoqc fields in TypeScript?tqlQ80ROP:
zspadWhat is one thing you would change about TypeScript?bssam
Q81Sbb:
dfsHow the xzeovneverbpj datatype can be useful?sfk
neverbpj datatype can be useful?sfkCode Challenges
Q1BZ5:
nqnqbedIs that TypeScript code amuucfwkvalidoeoqugtwrrxza? Explain whysuzizak
Q2IH1I:
ytjjhiHow to make an array with a ddbsrurfwhplspecific lengthiwjihwzulbs or vlpzwglshzaarray elementsufwwidujms in TypeScript?gysigv
Q3v9X7q:
agavyywIs there a way to check for both xomvnulldae and zjaundefinedqfuvqdv in TypeScript?tspzo
nulldae and zjaundefinedqfuvqdv in TypeScript?tspzoQ4au0BS:
kckzsAre strongly-typed functions as parameters possible in TypeScript?bqcdus
Q5tmv:
fvdWhat's vmpqpfdokmpxwrongwdvbhkzh with that code?wtpbnsf
Q62sfCq:
nridirWhat will be result of this code execution? itxmxhn
Q7eGzik:
cgwzkHow would you uamrutgqcpoverloadycmqptri a class constructor in TypeScript?wjg
Q8XP5LI:
qwweIn plqa?.b.ccsferu, if hmqftja.bnnsfs is vbfkanullmzxuqny, then coka.b.cwdmipma will evaluate to redosundefinedlkn, right?rwahhye
a?.b.ccsferu, if hmqftja.bnnsfs is vbfkanullmzxuqny, then coka.b.cwdmipma will evaluate to redosundefinedlkn, right?rwahhyeQ9510Ue:
djehuoExplain why that code is marked as sermldWRONGeinlnee?xclysvk
Q10o96:
ervmzvWhat does the zfvruconstioz assertion mean in TypeScript?wxt
constioz assertion mean in TypeScript?wxtRust has been Stack Overflow’s most loved language for four years in a row and emerged as a compelling language choice for both backend and system developers, offering a unique combination of memory safety, performance, concurrency without Data races...
Clean Architecture provides a clear and modular structure for building software systems, separating business rules from implementation details. It promotes maintainability by allowing for easier updates and changes to specific components without affe...
Azure Service Bus is a crucial component for Azure cloud developers as it provides reliable and scalable messaging capabilities. It enables decoupled communication between different components of a distributed system, promoting flexibility and resili...
Cosmos DB has gained popularity among developers and organizations across various industries, including finance, e-commerce, gaming, IoT, and more. Follow along and learn the 24 most common and advanced Azure Cosmos DB interview questions and answers...
More than any other NoSQL database, and dramatically more than any relational database, MongoDB's document-oriented data model makes it exceptionally easy to add or change fields, among other things. It unlocks Iteration on the project. Iteration f...
Unit Tests and Test Driven Development (TDD) help you really understand the design of the code you are working on. Instead of writing code to do something, you are starting by outlining all the conditions you are subjecting the code to and what outpu...
Domain-Driven Design is nothing magical but it is crucial to understand the importance of Ubiquitous Language, Domain Modeling, Context Mapping, extracting the Bounded Contexts correctly, designing efficient Aggregates and etc. before your next DDD p...
At its core, Microsoft Azure is a public cloud computing platform - with solutions including Infrastructure as a Service (IaaS), Platform as a Service (PaaS), and Software as a Service (SaaS) that can be used for services such as analytics, virtual c...
As an asynchronous event-driven JavaScript runtime, Node.js is designed to build scalable network applications. Follow along to refresh your knowledge and explore the 52 most frequently asked and advanced Node JS Interview Questions and Answers every...
Dependency Injection is most useful when you're aiming for code reuse, versatility and robustness to changes in your problem domain. DI is also useful for decoupling your system. DI also allows easier unit testing without having to hit a database and...
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