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Practice

Variable Declaration Keyword - let

let is one of the keywords used to declare variables in JavaScript.

Like var, it serves to store data but with some important differences.

Variables declared using let have block-level scope.

Similar to paragraphs or passages in a book, code also has sections enclosed by curly braces { }, known as 'blocks'.

let creates variables that are only accessible within this block.


Basic Usage​

You can declare a variable and assign a value using the let keyword.

Example:

let Variable Declaration
let schoolName = 'Lincoln High School';

In this example, the variable named schoolName holds the string value 'Lincoln High School'.


Characteristics of let Variables​

  1. Reassignable: Variables declared with let can be reassigned to different values.
Reassigning let Variable
let age = 15;
age = 16; // The value of the variable age is changed to 16.

  1. Block-Level Scope: Variables declared with let can only be accessed within the block, and its inner blocks, where it was declared.

Example:

let Variable Block-Level Scope
if (true) {
  let message = 'Hello!';
  console.log(message); // Outputs 'Hello!'
}

// The message variable cannot be used here.

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