Function Declaration vs Function Expression

A Function Declaration defines a function using the function keyword with a name.

Syntax-

function add(a, b) {
return a + b;
}
Key Points-

• Hoisted (can be used before it is defined)

• Has a function name

• Commonly used for reusable logic

  Example

  console.log(add(2, 3)); // ✅ Works
  
  function add(a, b) {
   return a + b;
  }
  
  

  

2️⃣ Function Expression

A Function Expression assigns a function to a variable.

Syntax

const add = function(a, b) {
 return a + b;
};

Key Points

• Not hoisted like function declarations

• Stored in a variable

• Can be anonymous

Example

console.log(add(2, 3)); // ❌ Error

const add = function(a, b) {
 return a + b;
};

Function Declaration vs Function Expression

3️⃣ Arrow Functions in JavaScript

What are Arrow Functions?

Arrow functions are a shorter syntax for writing function expressions.

Syntax

const add = (a, b) => a + b;

Arrow Function vs Normal Function

Normal Function

function greet(name) {
return "Hello " + name;
}

Arrow Function

const greet = name => "Hello " + name;

✨ Why Arrow Functions Are Simpler

✅ Shorter syntax
✅ No function keyword
✅ Implicit return (for single expressions)