Arrow Functions

const add = (a, b) -> { return a + b; }
const add = (a, b) => return a + b;
const add = (a, b) => a + b;
The valid arrow function syntax is `const add = (a, b) => a + b;`. This demonstrates the concise body syntax where the expression following the arrow (`=>`) is implicitly returned without needing the `return` keyword or curly braces. When an arrow function takes multiple parameters, they must be enclosed in parentheses. For single expressions, the curly braces and `return` statement can be omitted, which is one of the key benefits of arrow functions for short operations. Option 1 uses an incorrect arrow symbol (`->`). Option 2 incorrectly includes the `return` keyword in a concise body (without curly braces). Option 4 is missing the required parentheses around multiple parameters. Note that for a single parameter (e.g., `x => x * 2`), the parentheses are optional, but they're required when there are no parameters (`() => result`) or multiple parameters.
const add = a, b => a + b;