What's the Deal with Arrays and Objects?

let dataTypesArr = ['string', 1, true, ['array'], {key: 'value'}];let dataTypesObj = {  string: 'string',  number: 4,  boolean: true,  array: [1, 2, 3],  object: {inner: true}};

console.log(dataTypesArr[0]); //This prints the value held at the                              //0 index which is 'string' here//For loops allow us to access all of the data if we wanted tofor(let i = 0; i < dataTypesArr.length; i++){  console.log(dataTypesArr[i])}//This loop prints whatever value is held at the i index during//that iteration, and it runs until it is out of data to iterate//through

console.log(dataTypesObj.number); //Prints value held at the                                   //'number' key, which is 4console.log(dataTypesObj['boolean']); //Prints value held at the                                     //'boolean' key, which is true//To loop through an object, you have to use a for-in loopfor(let key in dataTypesObj){  console.log(key); //This prints all of the keys  console.log(dataTypesObj[key]);} //Here you wouldn't put key in quotes because key is used as a//variable. If you used quotes, the program would try to find the//key named 'key'. This will print all of the values held at each//key.

//.push() and .unshift() add data to the end and beginning of the//array respectivelydatatypesArr.push(5); //adds 5 to the end of the arraydatatypesArr.unshift(10); //adds 10 to the beginning of the array//.pop() and .shift() remove data from the end and beginning of//the array respectivelydatatypesArr.pop(); //removes the last valuedatatypesArr.shift(); //removes the first value

//Say we want to add a new piece of data called namedataTypesObj.name = 'Dakota'; //Adds new key/value pair:                              //name: 'Dakota'dataTypesObj['age'] = 27; //Also works with bracket notation!//If we wanted to delete our newly created data, just use the//delete keyworddelete dataTypesObj.name; //deletes name: 'Dakota'delete dataTypesObj['age']; //deletes age: 27