𝗝𝗮𝘃𝗮𝗦𝗰𝗿𝗶𝗽𝘁 𝗙𝘂𝗻𝗰𝘁𝗶𝗼𝗻𝘀 𝗘𝘅𝗽𝗹𝗮𝗶𝗻𝗲𝗱

𝗝𝗮𝘃𝗮𝗦𝗰𝗿𝗶𝗽𝘁 𝗙𝘂𝗻𝗰𝘁𝗶𝗼𝗻𝘀 𝗘𝘅𝗽𝗹𝗮𝗶𝗻𝗲𝗱

Functions are reusable blocks of code. They perform specific tasks. Think of a function as a machine. You provide input. The machine processes it. It gives you an output.

Functions stop you from writing the same code over and over. If you need to print a message 100 times, you write one function instead of 100 lines of code.

Benefits of functions:

• Less code
• Easier to read
• Simple maintenance
• Better reusability

Naming your functions matters. Use names that describe the action.

• Use: calculateSalary() or getUserData()
• Avoid: a() or xyz()

Rules for names:

• Use letters and numbers
• Do not start with a number
• Use underscores or dollar signs
• Do not use hyphens

Key parts of a function:

• Keyword: function
• Name: add
• Parameters: Placeholders for your inputs
• Body: The logic inside the curly braces
• Invocation: Calling the function to make it run

Do not confuse parameters with arguments. Parameters are the placeholders. Arguments are the actual values you pass in.

Return vs Console.log: Many beginners mix these up.

• console.log prints a value to the screen. You cannot use that value later.
• return sends a value back to your code. You can store it in a variable or use it in another calculation.

Professional developers use return to keep code flexible.

Three ways to write functions:

1. Function Declaration: function add(a, b) { return a + b; }
2. Function Expression: const add = function(a, b) { return a + b; };
3. Arrow Functions: const add = (a, b) => a + b;

Arrow functions are standard in modern frameworks like React.

Commonly used methods:

• Math: Math.max(), Math.random(), Math.floor()
• Strings: toUpperCase(), trim(), includes()
• Arrays: push(), pop(), map(), filter()
• Timers: setTimeout(), setInterval()

Break your large applications into small, manageable functions. It makes testing and fixing bugs much easier.

Source: https://www.geeksforgeeks.org/javascript/functions-in-javascript/ Source: https://www.w3schools.com/js/js_functions.asp

Full post: https://dev.to/dev_saravanan_journey/javascript-functions-explained-1706