JavaScript Objects

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JavaScript Objects

You can use JavaScript objects to store and manipulate data. JavaScript objects are written with key-value pairs, where each value can be of any data type. They are mutable, meaning you can modify their properties. For example, you could modify the name property of the person object below by assigning it a new value, such as 'Jane'. JavaScript objects also have built-in methods that allow you to perform various operations on the object.

What are JavaScript objects?

JavaScript objects are data structures used to store and organize related data. They consist of key-value pairs, where the key is a string and the value can be of any data type. Objects allow you to represent complex entities and their attributes in a structured way.

What are the types of JavaScript objects?

There are several types of JavaScript objects, including:

1. Object: The base object type in JavaScript. It is the parent of all other object types, such as arrays, functions, and dates.
2. Array: A special type of object used to store ordered collections of data.
3. Function: A reusable block of code that performs a specific task.
4. Date: Represents dates and times in JavaScript.
5. Math: Provides mathematical functions and constants.

JavaScript Objects Example

// JavaScript object example
// Create a JavaScript object called person
var person = {
  name: 'John',
  age: 30,
  city: 'New York'
};

// Loop through the properties of the JavaScript object
for (var key in person) {
  document.write(key + ': ' + person[key] + '<br/>');
}

FAQ (Interview Questions and Answers)

1. What are JavaScript objects?
   JavaScript objects are data structures used to store and manipulate data.
   JavaScript objects are reserved keywords in the language.
   JavaScript objects are used for arithmetic calculations.
   
2. What are the types of JavaScript objects?
   Strings, numbers, and booleans.
   Object, array, function, date, and math.
   Variables, constants, and operators.
   
3. Are JavaScript objects mutable?
   Yes, JavaScript objects can be modified after they are created.
   No, JavaScript objects cannot be changed once defined.
   It depends on the type of object.
   
4. What are JavaScript object methods?
   Built-in functions provided by JavaScript.
   Functions that are properties of JavaScript objects.
   Methods are not supported in JavaScript.
   
5. How can you access properties of a JavaScript object?
   By using dot notation or bracket notation.
   Only by using dot notation.
   By using function calls.
   

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