objects-with-functions.md

Using objects with functions

The function will allow me to pull data from the myBook object. It does this by passing the argument book and then the key within the object we want to collect so book.title for example.

let getSummary = (book) => {
    return {
        summary: `${book.title} by ${book.author}`,
        summaryPageCount: `${book.title} is ${book.pageCount} long`,
    };
};

To get the return statement to return the information from the book object, we have to pass this when calling the function. Such as let bookSummary = getSummary(myBook)

Full example below:

let myBook = {
    title: '1984',
    author: 'George Orwel',
    pageCount: 326,
};

let otherBook = {
    title: 'A Peoples History',
    author: 'Howard Zinn',
    pageCount: 723,
};

let getSummary = (book) => {
    return {
        summary: `${book.title} by ${book.author}`,
        summaryPageCount: `${book.title} is ${book.pageCount} long`,
    };
};

let bookSummary = getSummary(myBook);
console.log(bookSummary);
// prints ---
// summary: '1984 by George Orwel',
// summaryPageCount: '1984 is 326 long'

let otherBookSummary = getSummary(otherBook);
console.log(otherBookSummary);
// prints ---
// summary: 'A Peoples History by Howard Zinn',
// summaryPageCount: 'A Peoples History is 723 long'

// Another Example
let tempConversion = (fahrenheit) => {
    return {
        fahrenheit: fahrenheit,
        celsius: ((fahrenheit - 32) * 5) / 9,
        kelvin: ((fahrenheit + 459.67) * 5) / 9,
    };
};

let conversion = tempConversion(745);
console.log(conversion.celsius); // returns the celsius value