task-array.js

// EXERCISE:
// You can write all the code natively (for cycles and such) or you can use some advanced functions which JS arrays provides in case you see them fit
// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array
// There can be multiple solutions to each task, solve it as you see fit.
// You will work with array `numbers` which will be generated by code (code below) in every task.
// Write these functions:

// This block generates array with random length with values between 1-100
let numbers = [];
const length = Math.ceil(Math.random() * 10) + 5;
for (let i = 0; i < length; i = i + 1) {
  numbers.push(Math.ceil(Math.random() * 100));
}

// a) Function which will print to console a whole array
const printArray = (numbers) => {
  numbers.forEach((number) => {
    console.log(number);
  });
};

// b) Function which will print to console the length of array
const printLength = (numbers) => {
  console.log(numbers.length);
};

// c) Function which will print to console the first element of array
const printFirstItem = (numbers) => {
  if (numbers.length > 0) {
    console.log(numbers[0]);
  }
};

// d) Function which will print to console the last element
const printLastItem = (numbers) => {
  if (numbers.length > 0) {
    console.log(numbers[numbers.length - 1]);
  }
};

// e) Function which will print to console the largest number (You can check Math functions)
const printLargestItem = (numbers) => {
  console.log(Math.max(...numbers));
};

// f) Function which will print to console the smallest number (You can check Math functions)
const printSmallestItem = (numbers) => {
  console.log(Math.min(...numbers));
};

// g) Function which will print to console the sum of all numbers in array (You can check reduce function)
const printSum = (numbers) => {
  console.log(numbers.reduce((a, b) => a + b, 0));
};

// h) Function which will print to console the difference between the largest and the smallest number (You can check Math functions)
const printSALDifference = (numbers) => {
  console.log(Math.max(...numbers) - Math.min(...numbers));
};

// i) Function which will print to console the average of all numbers (You can check reduce function)
const printAverage = (numbers) => {
  console.log(numbers.reduce((a, b) => a + b, 0) / numbers.length);
};

// j) Function which will print to console the index of largest number (You can check Math functions)
const printLargestsIndex = (numbers) => {
  console.log(numbers.indexOf(Math.max(...numbers)));
};

// k) Function which will print to console the even numbers (not the array of even numbers),
// if array doesn't contain any even number, show text "Even number isn't in array"
const printEvenNums = (numbers) => {
  let printed = false;
  numbers.forEach((number) => {
    if (number % 2 === 0) {
      console.log(number);
      printed = true;
    }
  });

  if (!printed)
    console.log("Even number isn't in array");
};

// l) Function which will multiple by 2 every number in array and print the array to console
// Example: printNumsMultipliedBy2([1,2,3]) -> [2,4,6]
const printNumsMultipliedBy2 = (numbers) => {
  numbers.forEach((number, index) => {
    numbers[index] = number * 2;
    console.log(numbers[index]);
  });
};

/*
   Print implemented stuff
 */

console.log("\nPrint array:");
printArray(numbers);

console.log("\nPrint length:");
printLength(numbers);

console.log("\nPrint first item:");
printFirstItem(numbers);

console.log("\nPrint last item:");
printLastItem(numbers);

console.log("\nPrint largest item:");
printLargestItem(numbers);

console.log("\nPrint smallest item:");
printSmallestItem(numbers);

console.log("\nPrint sum:");
printSum(numbers);

console.log("\nPrint difference between largest and smallest:");
printSALDifference(numbers);

console.log("\nPrint average:");
printAverage(numbers);

console.log("\nPrint index of largest number:");
printLargestsIndex(numbers);

console.log("\nPrint even numbers:");
printEvenNums(numbers);

console.log("\nPrint numbers multiplied by 2:");
printNumsMultipliedBy2(numbers);