05-basic-data-structures.md

Introduction to the Basic Data Structure Challenges

https://www.freecodecamp.org/learn/javascript-algorithms-and-data-structures/basic-data-structures

How do I add an item to the start of an array?

array.unshift(...args)

How do I remove elements in the middle of an array?

array.splice(index, numberOfElements);

How do I replace elements in the middle of an array?

array.splice(index, numberOfElementsToDelete, ...elementsToAdd);

How do I extract elements from an array without changing the array?

array.slice(indexToStartInclusive, indexToEndExclusive)

How do I copy an array?

let newArr = [...oldArr]

How do I insert an array in another array?

let thatArray = ['basil', 'cilantro', ...thisArray, 'coriander'];

How do I get the index of an element in an array?

fruits.indexOf('dates')

What is the result of indexOf if the element does not exist?

-1

How do I remove a property from an object?

delete object.property

How do I check if an object has a property?

users.hasOwnProperty('Alan');
'Alan' in users;

How do I iterate through the keys of an object?

for (let user in users) {

}

How do I get the keys of an object?

Object.keys(obj)