wo17ek

function shallowCopy(target, ...sources) {
  if(arguments.length === 0) {
    return null;
  }
  else if(arguments.length === 1) {
    if(target !== null && target !== undefined) {
      sources.unshift(target);
      target = {};
    }
    else {

wo17ek

/*
  Copy relies on assigning each source object property into the target with corresponding names.
*/
const source = {
  number: 1,
  object: {
    string: "I like cookies",
    array: [1, 2, 3]
  }
};

wo17ek

source.number = 10;
source.object.string = "I like them too!";
source.object.array = [4, 5, 6];

console.log('source: ', source, 'target: ', target); // output presented below

wo17ek

source.object.string = "I like them too!";
source.object.array = [4, 5, 6];

console.log('source.object === target.object: ', source.object === target.object) // true, 
console.log('source: ', source, 'target: ', target); // output presented below

wo17ek

/*
  PART 1: assign a non-primitive variable into another.
*/
let source = {
  number: 1,
  object1: {
    string: "I like cookies."
  },
  object2: {
    string: "You dared to eat my cookies!"

wo17ek

source.number = 10;

console.log('source: ', source,'target: ', target); // output presented below

wo17ek

source.number = 10;
source.object = {
  string: "Where did my cookies go?" 
}

console.log('source.object === target.object: ', source.object === target.object) // true, so both store the same reference
console.log('source: ', source, 'target: ', target); // output presented below

wo17ek

/*
  Copy relies on assigning each source object property into the target with corresponding names.
*/
const source = {
  number: 1,
  object: {
    string: "I like cookies",
    array: [1, 2, 3]
  }
};

wo17ek

const source = {
  number: 1,
  object: {
    string: "I like cookies"
  }
};
const target = source;

console.log(source === target) // true, so they both store reference to the same place. 
console.log('source: ', source,'target: ', target); // output presented below

wo17ek

let source = 1,
    target = source;

console.log('source: ', source,'target: ', target);

source = 10;

console.log('source: ', source,'target: ', target);