Q1131. What are the array mutation methods?
JavaScript array methods can be categorized into two groups: 1. Mutating methods: These are the methods that directly modify the original array. 1. Non-mutating methods: ...
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Q1132. What is module scope in JavaScript?
Module scope is a feature introduced with ES6 (ES2015) modules that creates a scope specific to a module file, isolating variables and functions declared within it from t...
Q1133. What are shadowing and illegal shadowing?
Both **shadowing** and **illegal shadowing** refer to how variable names can "hide" or override others within nested scopes. **Shadowing** occurs when a variable declared...
Q1134. Why is it important to remove event listeners after use?
In JavaScript, you need to be mindful of removing event listeners to avoid memory leaks — especially in long-lived apps like single-page applications (SPAs) or when worki...
Q1135. What is structuredClone and how is it used for deep copying objects?
In JavaScript, `structuredClone()` is a built-in method used to create a **deep copy** of a value. It safely clones nested objects, arrays, Maps, Sets, Dates, TypedArrays...
Q1136. What is the difference between const and Object.freeze?
The main difference is that `const` applies to **variables** (bindings), while `Object.freeze()` applies to **values** (objects). 1. **`const`**: Prevents the reassignmen...
Q1137. What is BigInt and how is it different from Number?
`BigInt` is a built-in JavaScript object (introduced in ES2020) that provides a way to represent whole numbers larger than 2^53 - 1 (the largest number JavaScript can rel...
Q1138. What are private class fields in JavaScript?
Private class fields (introduced in ES2022) are class properties that are only accessible within the class itself. They are prefixed with a hash symbol (`#`) and provide ...
Q1139. What are WeakRef and FinalizationRegistry used for?
`WeakRef` and `FinalizationRegistry` are advanced features (introduced in ES2021) for managing memory and object lifecycles in JavaScript. They provide low-level control ...
Q1140. What are logical assignment operators?
Logical assignment operators (introduced in ES2021) combine logical operations (`&&`, `||`, `??`) with assignment (`=`). They provide a concise way to assign values based...