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Scope

Practice Good Scoping

  1. Avoid Global Variables Global variables can lead to unexpected side effects and make code difficult to debug. Encapsulate variables within appropriate scopes to maintain control.
    1// Avoid
    2globalVar = 'I am global';
    3
    4// Prefer
    5function myFunction() {
    6 let localVar = 'I am local';
    7}
  2. Use Function Scope Localize variables within function scopes to prevent name conflicts and encourage modular programming.
    1function calculateArea(radius) {
    2 const PI = 3.14159;
    3 return PI * radius * radius;
    4}
  3. Declare Variables Properly Use let or const instead of var to create block-scoped variables, restricting their usage to the appropriate scope.
    1if (true) {
    2 let blockScopedVar = 'I am confined to this block';
    3 }
  4. Avoid Reusing Variable Names Descriptive names that represent the purpose and context of variables prevent confusion and errors.
    1// Avoid
    2let name = 'John';
    3function greet() {
    4 let name = 'Doe';
    5}
    6
    7// Prefer
    8let firstName = 'John';
    9function greet() {
    10 let lastName = 'Doe';
    11}
  5. Use Proper Naming Conventions Clear and descriptive names improve readability and reduce scope-related issues.
    1// Descriptive naming
    2let userAge = 25;
    3function calculateDiscount(price) { /* ... */ }

Instructions

1.

Declare another function showLocalVar() inside the checkScope() function.

2.

Inside the showLocalVar() function, console.log the variable localVar.

3.

Call the showLocalVar() function inside checkScope() function.

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