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JavaScript Basics for Absolute Beginners interview questions
Answer aloud before opening each explanation. Focus on the reasoning, not memorized wording.
0/6 saved answers | 6 questions shown
01What is the difference between == and ===?TypesBeginner
Model answer
== performs coercion; === compares without coercing types.
Why
Strict equality is usually clearer because it avoids surprising conversion rules.
02What is a closure?ScopeBeginner
Model answer
A function together with access to the lexical environment where it was created.
Why
Closures power private state, callbacks, factories, and many asynchronous patterns.
03How does the prototype chain work?ObjectsIntermediate
Model answer
Property lookup continues through linked prototype objects until found or null.
Why
JavaScript inheritance is delegation through prototypes, even when class syntax is used.
04What does await do?AsyncIntermediate
Model answer
It pauses that async function until a promise settles without blocking the event loop.
Why
Other queued work can continue while the awaited operation is pending.
05What is the event loop?RuntimeAdvanced
Model answer
The scheduling mechanism that runs tasks and microtasks when the call stack is clear.
Why
Promise reactions use the microtask queue, which is processed before the next task.
06How does this get its value?FunctionsAdvanced
Model answer
Usually from the call site; arrow functions capture it lexically.
Why
Method calls, constructors, explicit binding, and plain calls establish different this values.