Solve this multiple-choice question and choose the correct option.

In JavaScript, which of the following is a correct way to create a new plain object instance?

Difficulty: Easy

By using an object literal such as var obj = {}; which creates a new empty object.
By declaring var obj; without assigning anything, which automatically creates a new object.
By writing create object obj; which is a built in JavaScript statement.
By writing var obj = new Object[]; which creates a new object without using parentheses.
By calling window.object(); which always returns a fresh generic object.

Correct Answer: By using an object literal such as var obj = {}; which creates a new empty object.

Explanation:

Introduction / Context:

Creating objects is central to JavaScript programming. Unlike some languages that require verbose class syntax for every object, JavaScript supports flexible object creation patterns. The most common way to create a simple, plain object is to use an object literal, written with curly braces.

Given Data / Assumptions:

The question is asking about creating a new plain JavaScript object, not an array or a DOM node.
We are working with basic JavaScript syntax as supported in all modern browsers.
Object literals are widely used in real world JavaScript code.

Concept / Approach:

JavaScript objects are essentially collections of key value pairs. An object literal is written as a pair of curly braces optionally containing property definitions. For example, var person = { name: 'Alex', age: 30 }; creates a new object with two properties. An empty object literal, {}, creates a new plain object with no own properties. This is equivalent to new Object(), but the literal form is shorter, clearer, and more idiomatic in modern code.

Step-by-Step Solution:

Step 1: Recall that {} is the primitive syntax for creating a new plain object literal. Step 2: Understand that assigning this literal to a variable with var, let, or const stores a reference to the new object. Step 3: Compare this with simply declaring a variable without assignment, which does not automatically create an object instance. Step 4: Verify that constructs like create object or window.object() are not part of the standard JavaScript language. Step 5: Choose the option that shows var obj = {}; as the correct object creation pattern.

Verification / Alternative check:

A developer can open the browser console and type var obj = {}; then type obj to see the resulting object. The console displays an empty object, confirming that this syntax creates a new object each time it is used. Typing var x; without assignment yields undefined, demonstrating that a declaration alone does not allocate an object.

Why Other Options Are Wrong:

Option B is wrong because var obj; only declares a variable and leaves it with the value undefined. Option C is wrong because there is no create object statement in JavaScript; this is not valid syntax. Option D is wrong because new Object[] resembles array syntax from other languages and is not a correct JavaScript pattern for plain objects. Option E is wrong because window.object() is not a standard function provided by browsers.

Common Pitfalls:

A common pitfall is confusing plain objects with arrays; arrays use [] syntax, while objects use {}. Another mistake is forgetting to initialize the object before using it, leading to runtime errors when trying to access properties of undefined. Using object literals consistently helps create clear, concise data structures in JavaScript.

Final Answer:

The correct choice is By using an object literal such as var obj = {}; which creates a new empty object. because this syntax is the standard and most concise way to create a new plain object in JavaScript.

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In JavaScript, which of the following is a correct way to create a new plain object instance?

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