Q701. What is optional chaining?
According to MDN official docs, the optional chaining operator (?.) permits reading the value of a property located deep within a chain of connected objects without havin...
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Q702. What are the features of create react app?
Below are the list of some of the features provided by create react app. 1. React, JSX, ES6, Typescript and Flow syntax support. 2. Autoprefixed CSS 3. CSS Reset/Normaliz...
Q703. What is an environment record?
According to ECMAScript specification 262 (9.1): > [Environment Record](https://262.ecma-international.org/12.0/#sec-environment-records) is a specification type used to ...
Q704. How to verify if a variable is an array?
It is possible to check if a variable is an array instance using 3 different ways, 1. Array.isArray() method: The `Array.isArray(value)` utility function is used to deter...
Q705. What is pass by value and pass by reference?
Pass-by-value creates a new space in memory and makes a copy of a value. Primitives such as string, number, boolean etc will actually create a new copy. Hence, updating o...
Q706. What are the differences between primitives and non-primitives?
JavaScript language has both primitives and non-primitives but there are few differences between them as below, | Primitives | Non-primitives | | ------------------------...
Q707. How do you create your own bind method using either call or apply method?
The custom bind function needs to be created on Function prototype inorder to use it as other builtin functions. This custom function should return a function similar to ...
Q708. What are the differences between pure and impure functions?
Some of the major differences between pure and impure function are as below, | Pure function | Impure function | | ----------------------------------- | -----------------...
Q709. What is referential transparency?
An expression in javascript that can be replaced by its value without affecting the behaviour of the program is called referential transparency. Pure functions are refere...
Q710. What are the possible side-effects in javascript?
A side effect is the modification of the state through the invocation of a function or expression. These side effects make our function impure by default. Below are some ...