Lecture 147:- Square Bracket Notation

Square bracket notation is a way of accessing and manipulating values in objects and arrays in JavaScript.

In objects, square bracket notation allows you to access properties using a string or a variable that holds a string. For example:

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const person = { name: 'John', age: 30 }; console.log(person['name']); // Output: 'John' const propertyName = 'age'; console.log(person[propertyName]); // Output: 30

In arrays, square bracket notation is used to access elements by their index position. For example:

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const numbers = [1, 2, 3, 4, 5]; console.log(numbers[0]); // Output: 1 const index = 2; console.log(numbers[index]); // Output: 3

Square bracket notation is useful when the name of a property or an element index is stored in a variable or passed as a parameter to a function.