jasminegmp

var a = 'hi';
function myFunction(){
    var a; // the a in the local scope is hoisted here and a is 'undefined
    console.log(a); // outputs 'undefined
    a = 'hello';
    console.log(a); // outputs 'hello'
}

jasminegmp

function myFunction(){
    a;
    console.log(a);
    let a = 'hello';
}
myFunction(); 

jasminegmp

function myFunction(){
    let a; // a's declaration is hoisted here, but remains uninitialized
    a // Will get a ReferenceError: Cannot access 'a' before initialization
    console.log(a);
}
myFunction(); 

jasminegmp

function myFunction(){
    let a; // a's declaration is hoisted here, but remains uninitialized
    a; // Will get a ReferenceError: Cannot access 'a' before initialization
    console.log(a);
    a = 'hello'; // everything above this line of code is referenced as temporal dead zone
}
myFunction(); 

jasminegmp

import React from 'react';

class Parent extends React.Component{
    constructor(props){
        super(props);
        this.state = {
            data: 'Data from parent'
        }
    }

jasminegmp

import React from 'react';

function Parent(){
    const data = 'Data from parent';
    return(
        <div>
            <Child dataParentToChild = {data}/>
        </div>
    )
}

jasminegmp

import React from 'react';

class Parent extends React.Component{
    constructor(props){
        super(props);
        this.state = {
            data: null
        }
    }