funcPatterns for JS

funcPatterns.js

let getDimentions = (length, height) => ({length, height});
// It is same as
getDimentions = (length, height) => {
    return {length: length, height: height};
};


// function arguments defaults: Old way
getDimentions = (length, height) => {
  if (!length) {
    length = 0;
  }
  if (!height) {
    height = 0;
  }
  return {length, height};
};
// Better Way: function default parameters
getDimentions = (length = 0, height = 0) => ({length, height});

// destructuring
let {height} = getDimentions(23, 56);

// default functions object parameters
let getRGB = ({r,g,b}) => `color: (${r}, ${g}, ${b});`;
 // It is same as
 getRGB = (color) => {
    const r = color.r;
    const g = color.g;
    const b = color.b;
    return  `color: (${r}, ${g}, ${b});`; // or 'color: (' + r + '), (' + g + '), (' + b ');';
 };
 
 // Default for Object
getRGB = ({r,g,b} = {r: '', g: '', b: ''}) => `color: (${r}, ${g}, ${b});`;

 // What if I want default for Object parameters
getRGB = ({r = '',g = '',b = ''} = {r: '', g: '', b: ''}) => `color: (${r}, ${g}, ${b});`;

// Tag function (with template literals)
let greet = (...arguments) => {
  console.log(arguments);
}
let name = 'Joe';
let age = 22; 
greet`I'm ${name}. I'm ${age} years old.`;

greet = (strings, ...values) => {
  console.log(strings, values);
}

// We would get following
// strings = ['I'm ', '. I'm ', ' years old.']
// values = ['Joe', 22]