General Coding Standards
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Meaningful Names:
- Use meaningful and descriptive variable and function names.
- Avoid abbreviations and single-letter names except for loop counters.
// Good const userAge = 25; function calculateTotalPrice(items) { ... } // Bad const a = 25; function calc(items) { ... }
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Consistent Naming Conventions:
- Use camelCase for variables and functions.
- Use PascalCase for class names.
const userAge = 25; function calculateTotalPrice(items) { ... } class UserProfile { ... }
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Avoid Repetition:
- Follow the DRY (Don’t Repeat Yourself) principle by encapsulating repeated code into functions.
// Good function calculateDiscount(price, discount) { ... } const price1 = calculateDiscount(100, 10); const price2 = calculateDiscount(200, 20); // Bad const price1 = 100 - 10; const price2 = 200 - 20;
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Error Handling:
- Wrap API calls and other asynchronous operations in try-catch blocks.
async function fetchData() { try { const response = await fetch('api/url'); const data = await response.json(); return data; } catch (error) { console.error('Error fetching data:', error); } }
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Edge Cases:
- Always consider edge cases and validate inputs.
function getUserAge(user) { if (!user || !user.age) { return 'Age not available'; } return user.age; }
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Consistent Formatting:
- Follow a consistent code formatting style (indentation, spacing, etc.). Use tools like Prettier to automate this.
if (condition) { doSomething(); } else { doSomethingElse(); }
Code Organization
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Modularization:
- Break down the code into small, reusable modules or functions.
// utils.js export function calculateDiscount(price, discount) { ... } // main.js import { calculateDiscount } from './utils.js';
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Separation of Concerns:
- Separate different concerns (e.g., UI logic, business logic, data handling) into different files or functions.
// ui.js function updateUI(data) { ... } // data.js async function fetchData() { ... } // main.js import { updateUI } from './ui.js'; import { fetchData } from './data.js';
Best Practices
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Use Strict Mode:
- Always enable strict mode to catch common coding errors.
'use strict';
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Use Constants:
- Use constants for values that do not change.
const MAX_USERS = 100;
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Avoid Global Variables:
- Minimize the use of global variables to avoid conflicts and unintended behavior.
// Good (function() { const localVariable = 'This is local'; })(); // Bad var globalVariable = 'This is global';
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Commenting and Documentation:
- Write comments and documentation to explain the purpose and functionality of the code.
/** * Calculates the total price after applying a discount. * @param {number} price - The original price. * @param {number} discount - The discount to apply. * @returns {number} - The total price after discount. */ function calculateTotalPrice(price, discount) { ... }
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Use Promises and Async/Await with Error Handling:
- Prefer using promises and async/await for asynchronous operations, and wrap them in try-catch blocks for error handling.
// Good async function fetchData() { try { const response = await fetch('api/url'); const data = await response.json(); return data; } catch (error) { console.error('Error fetching data:', error); } } // Bad function fetchData(callback) { fetch('api/url') .then(response => response.json()) .then(data => callback(data)) .catch(error => console.error('Error fetching data:', error)); }
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Object Destructuring:
- Use object destructuring to extract multiple properties from an object in a concise way.
// Good const vehicle = { make: 'Toyota', model: 'Camry' }; const { make, model } = vehicle; // Bad const vehicleMake = vehicle.make; const vehicleModel = vehicle.model;
By following these standards, you can ensure that your JavaScript code is clean, maintainable, and efficient.