week4.js

/***** Converting Between Arrow and Normal Functions *****/

// Normal Function
function isJose(user) {
    return user.username === "jose"
}

// Arrow Function
const isJose = (user) => {
    return user.username === "jose"
}

// Get rid of the parenthesis around one parameter (if you want)
const isJose = user => {
    return user.username === "jose"
}

// Get rid of the parenthesis around one parameter (if you want)
const isJose = user => user.username === "jose"


function isNotEmpty(paper) {
    return paper !== "";
}

const isNotEmpty = (paper) => {
    return paper !== "";
}

const isNotEmpty = paper => {
    return paper !== "";
}

const isNotEmpty = paper => paper !== ""

const isNotEmpty = p => p !== ""


name => "Hello " + name

name => {
    return "Hello " + name
}

(name) => {
    return "Hello " + name
}

function makeGreeting(name) {
    return "Hello " + name
}



/***** Array Methods *****/

const emailList = [
    {
        id: 234,
        author: "Natalie",
        to: "Calvin",
        message: "Heyyyy",
        read: false,
    },
    {
        id: 1654,
        author: "Natalie",
        to: "Calvin",
        message: "What's up?",
        read: true,
    },
    {
        id: 474,
        author: "Dylan",
        to: "Calvin",
        message: "Good day",
        read: false,
    }
]

alert(  emailList.map(   email => email.author + " - " + email.message   ).join("\n")   );

alert(  emailList.map(   email => email.author + ":\n" + email.message   ).join("\n\n")   );

alert( emailList.map(   function(email) {
    return email.author + " - " + email.message  
}) );


const unreadEmails = emailList.filter( email => !email.read ).map(   email => email.author + ":\n" + email.message   ).join("\n\n")
alert(unreadEmails);

// We CAN do map then filter, we just don't tend to
const emailStringsThatStartWithN = emailList.map(   email => email.author + ":\n" + email.message   ).filter( stringOfEmail => stringOfEmail[0] === "N" ).join("\n\n")


alert( emailList.find( message => message.id === 1654 ).author )

const idToFind = 1654
const emailWithId = emailList.find( message => message.id === idToFind )
console.log( emailWithId.author )

// Challenge: make a function that takes an id as a parameter and returns the author of the email with that id