The Javascript Let keyword
 

The Javascript Let keyword

The Javascript let keyword is more prescriptive than the simple var assignment of vsriables.

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The AI solution/explanation is show below:

In JavaScript, the let keyword is used to declare variables. It was introduced in ES6 (ECMAScript 2015) and is preferred over var in many cases due to its block-scoping and improved behavior. Here's a quick overview:

Key Features of let:
Block Scope: Variables declared with let are limited to the block, statement, or expression where they are defined.
No Hoisting Issues: Unlike var, let does not allow access to the variable before its declaration (temporal dead zone).
Reassignment Allowed: You can reassign values to a let variable, but you cannot redeclare it in the same scope.
Example Usage:

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<script>
// Block Scope Example
if (true) {
let message = "Hello, block scope!";
console.log(message); // Output: Hello, block scope!
}
// console.log(message); // Error: message is not defined

// Reassignment Example
let count = 10;
count = 20; // Works fine
console.log(count); // Output: 20

// Temporal Dead Zone Example
console.log(name2); // Output Uncaught ReferenceError: Cannot access 'name' before initialization
let name = "Alice";
console.log(name); // Output: Alice
</script>

When to Use let:
Use let when you need a variable whose value might change and is scoped to a specific block of code.
For constants or values that should not change, use const instead.

The scoping of the variables can be seen using console.

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References - a note on these

  • JavaScript Let - https:// www.w3schools.com/JS/ js_let.asp
  • - https:// developer.mozilla.org/ en-US/docs/Web/JavaScript/ Reference/ Statements/let
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