Yigaue

<?php
 
/** 

| The commented code shows the full code of the ternary equiv.
*/

//  if ($age = 20 < 22)
 
//  {

Yigaue

let data  = [
    {id: 1, title: "Don't Waste your life ", price: 33, Author: "John Piper"},
    {id: 2,  title: "Living for a greater purpose", price: 12, Author: "JH Baritam"},
    {id: 3, title: "The call for Mercy", price: 405, Author: "Lekia Yiga"},
    {id: 4, title: "Heart Blindness", price: 550, Author: "Unknown author"}
];

Yigaue

let newPrice = data.map((book) => book.price + 200);
console.log(newPrice);

// result:

// (4) [233, 212, 605, 750]

Yigaue

data.map(item => {
    if (item.price > 100) {
        return {
            id: item.id,
            title: item.title,
            price: item.price * (1 - 0.2)
        };
    }
    return item;
});

Yigaue

let data  = [
    {id: 1, title: "Don't Waste your life ", price: 33, Author: "John Piper"},
    {id: 2,  title: "Living for a greater purpose", price: 12, Author: "JH Baritam"},
    {id: 3, title: "The call for Mercy", price: 405, Author: "Lekia Yiga"},
    {id: 4, title: "Heart Blindness", price: 550, Author: "Unknown author"}
];
let discountedBooks = data.filter(item => item.price > 100);
console.log(discountedBooks);
//result
/*

Yigaue

let data  = [
    {id: 1, title: "Don't Waste your life ", price: 33, Author: "John Piper"},
    {id: 2,  title: "Living for a greater purpose", price: 12, Author: "JH Baritam"},
    {id: 3, title: "The call for Mercy", price: 405, Author: "Lekia Yiga"},
    {id: 4, title: "Heart Blindness", price: 550, Author: "Unknown author"}
];
let discountedBooks = data.find(item => item.price > 100);
console.log(discountedBooks);

// result

Yigaue

let data  = [
    {id: 1, title: 'Nite watch', price: 33, discount:0},
    {id: 2,  title: 'what I want', price: 12, discount:0.4},
    {id: 3, title: 'Mercy at last', price: 405, discount:0.25},
    {id: 4, title: 'Nothting between', price: 550, discount:0}
];
let discountedBooks = data.some(item => item.discount > 0 );
console.log(discountedBooks);

// result

Yigaue

let data  = [
    {id: 1, title: 'Nite watch', price: 33, discount:0},
    {id: 2,  title: 'what I want', price: 12, discount:0.4},
    {id: 3, title: 'Mercy at last', price: 405, discount:0.25},
    {id: 4, title: 'Nothting between', price: 550, discount:0}
];
let discountedBooks = data.every(item => item.discount > 0 );
console.log(discountedBooks);

// result

Yigaue

let data  = [
    {id: 1, title: 'Nite watch', price: 33, discount:0},
    {id: 2,  title: 'what I want', price: 12, discount:0.4},
    {id: 3, title: 'Mercy at last', price: 405, discount:0.25},
    {id: 4, title: 'Nothting between', price: 550, discount:0}
];
priceSum = data.reduce((acc, currentValue) => acc + currentValue.price, 0);
console.log(priceSum);
// console result
1000

Yigaue

$permeabilityArray = [9230, 5940, 3080, 2860, 2790, 2370, 1464,  594,  593,  526,  500, 366];

/** 
* Each number in the array should take turns to divided it self and every other number in the array,
* and a number can only divide itself or a number that has index greater than it.
* E.g 9230 can divide itself and every other number. 3080 can not divide 5940, and 9230 but can divide 
* 2860, 2790, 2370, 1464,  594,  593,  526,  500, and 366.
* Print result different set of arrays. 
*/