Are these 2 JavaScript statements equivalent?

Question

These 2 statements seem to do the same thing.

const handleClick = () => alert('foo');

and

function handleClick() {
    alert('foo');
}

Are they identical and just syntactically different? The first one looks like a variable declaration, whereas the second one is clearly a function definition.

Answer 1

No, they are not the same thing. The arrow function has some limitations:

• Does not have its own bindings to this or super, and should not be used as methods.
• Does not have new.target keyword.
• Not suitable for call, apply and bind methods, which generally rely on establishing a scope.
• Can not be used as constructors.
• Can not use yield, within its body.

Answer 2

ES6 arrow functions provide you with an alternative way to write a shorter syntax compared to the function expression. There is no performance difference.

Are arrow functions faster (more performant, lighter) than ordinary standalone function declaration in v8?