Code Habit - Const Functions

code-habit-const-functions-1.js

// Preventing hoisting. We're used to reading top to bottom, so this can be quite confusing.
const result = add(1, 2);

function add(x, y) {
  return x + y;
};

console.log(result);

code-habit-const-functions-2.js

// Consistency between declarations and expressions. It's much clearer that functions are just data.
const add = (x, y) => {
  return x + y;
};

const resultFromDeclaration = add(1, 2);
const resultFromExpression = ((x, y) => {
  return x + y;
})(1, 2);

console.log(resultFromDeclaration);
console.log(resultFromExpression);

code-habit-const-functions-3.js

// Avoiding reassignment. This can cause confusion if the reassignment on line 6 isn't spotted.
let add = (x, y) => {
  return x + y;
};

add = (x, y, z) => {
  return x + y + z;
};

const result = add(1, 2, 3);

console.log(result);