msb-public
/
30-Days-Of-JavaScript
mirror of https://github.com/Asabeneh/30-Days-Of-JavaScript
1
0
Code Issues Projects Releases Wiki Activity

uploaded day9, day10

Browse Source
pull/949/head
Nevzat Atalay 2 years ago
parent 0e18986871
commit dc7cfb9284
2 changed files with 666 additions and 0 deletions
Show Stats Download Patch File Download Diff File

512
Exercise-Solutions/09_day_callbac_function.md
Unescape View File

@ -0,0 +1,512 @@
# Day 9 - High Order Function
## [Exercise:Solutions](#exercise-solutions)
- ### [Exercise:Level 1](#exercises-level-1)
- ### [Exercise:Level 2](#exercises-level-2)
- ### [Exercise:Level 3](#exercises-level-3) <hr>
#### [Home](../README.md) | [<< Day 6](./06_day_loops.md) | [Day 8 >>](./08_day_object.md)
## Exercise Solutions
### Exercises Level 1
```
const countries = ['Finland', 'Sweden', 'Denmark', 'Norway', 'IceLand']
const names = ['Asabeneh', 'Mathias', 'Elias', 'Brook']
const numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
const products = [
{ product: 'banana', price: 3 },
{ product: 'mango', price: 6 },
{ product: 'potato', price: ' ' },
{ product: 'avocado', price: 8 },
{ product: 'coffee', price: 10 },
{ product: 'tea', price: '' },
]
```
1. Explain the difference between forEach, map, filter, and reduce.
```
foreach dizideki her bir eleman için bir fonksiyon çalıştırir.Dizideki elemani degistirebilir ama yeni bir dizi olisturamaz.
map foreach ile aynidir farki map yeni bir dizi döndürür.
reduce, bir dizideki her öğe için belirtilen bir fonksiyonu çalıştırır ve bu fonksiyonun sonuçlarını biriktirerek tek bir değer döndürür. Bu fonksiyon, dizinin her öğesini değiştiremez, ancak bir önceki fonksiyon çağrısının sonucunu alarak bir sonraki fonksiyon çağrısına aktarır.
filrer JavaScript’te filter metodu, bir dizideki elemanları belirli bir koşula göre filtrelemek için kullanılan bir dizidir. Filter metodu, orijinal diziyi değiştirmez, ancak koşulu sağlayan elemanlardan oluşan yeni bir dizi döndürür
```
2. Define a callback function before you use it in forEach, map, filter or reduce.
```js
// app.js
const callback = (n) => {return n**2}
function cube(callback,n){
return callback(n) * n}
console.log(cube(callback,3))
```
3. Use forEach to console.log each country in the countries array.
```js
// app.js
const countries = ['turkiye','sırıa','japan','germany']
countries.forEach((element => console.log(element)) )
```
4. Use forEach to console.log each name in the names array.
```js
// app.js
const names = ['nevzat','atalay','gül','atalay']
names.forEach(name1 => console.log(name1))
```
5. Use forEach to console.log each number in the numbers array.
```js
// app.js
const numbers = [15,43, 56,78,25,2030]
numbers.forEach(num => console.log(num))
```
6. Use map to create a new array by changing each country to uppercase in the countries array.
```js
// app.js
const countries = ['turkiye','sırıa','japan','germany']
const upperCase =countries.map((upper) => upper.toUpperCase())
console.log(upperCase)
```
7. Use map to create an array of countries length from countries array.
```js
// app.js
const countries = ['turkiye','sırıa','japan','germany']
const newArr = countries.map((new1) => new1.length > 5)
console.log(newArr)
```
8. Use map to create a new array by changing each number to square in the numbers array
```js
// app.js
const numbers = [2,3,4,5,6]
const square = numbers.map((num) => num**2)
console.log(square)
```
9. Use map to change to each name to uppercase in the names array
```js
// app.js
const names = ['Asabeneh', 'Mathias', 'Elias', 'Brook']
const newArr = names.map((name1) => name1.toUpperCase())
console.log(newArr)
```
10. Use map to map the products array to its corresponding prices.
```js
// app.js
const products = [
{ product: 'banana', price: 3 },
{ product: 'mango', price: 6 },
{ product: 'potato', price: ' ' },
{ product: 'avocado', price: 8 },
{ product: 'coffee', price: 10 },
{ product: 'tea', price: '' },
];
// map metodu ile yeni bir dizi oluşturuyoruz
const productsWithPrices = products.map(function(product) {
// her nesnenin product ve price özelliklerini birleştiriyoruz
return product.product + ': ' + product.price;
});
// yeni diziyi yazdırıyoruz
console.log(productsWithPrices);
// ["banana: 3", "mango: 6", "potato: ", "avocado: 8", "coffee: 10", "tea: "]
```
11. Use filter to filter out countries containing land
```js
// app.js
const countries = ['Finland','Iceland','Grönland','Turkey','Germany']
const newArr = countries.filter((new1) => new1.includes('land'))
console.log(newArr)
```
12. Use filter to filter out countries having six character.
```js
// app.js
const countries = ['Finland','Icelan','Grönland','Turkey','Germany',]
const newArr = countries.filter((new1) => new1.length ==6)
console.log(newArr)
```
13. Use filter to filter out countries containing six letters and more in the country array
```js
// app.js
const countries = ['Finland','Iceland','Grönland','Turkey','Germany']
const newArr = countries.filter((new1) => new1.length > 6)
console.log(newArr)
```
14. Use filter to filter out country start with 'E';
```js
// app.js
const countries = ['Finland','Iceland','Grönland','Turkey','Germany','England','Estonia']
const newArr =countries.filter((new1) => new1.startsWith('E'))
console.log(newArr)
```
15. Use filter to filter out only prices with values.
```js
// app.js
const products = [
{ product: 'banana', price: 3 },
{ product: 'mango', price: 6 },
{ product: 'potato', price: ' ' },
{ product: 'avocado', price: 8 },
{ product: 'coffee', price: 10 },
{ product: 'tea', price: '' },
];
const filteredProducts = products.filter(product => product.price !== '' && product.price !== ' ');
console.log(filteredProducts);
```
16. Declare a function called getStringLists which takes an array as a parameter and then returns an array only with string items.
```js
// app.js
const arr = ['ali', 'veli', 'küpeli']
function getStringList(){
let newArr= []
arr.map(string => newArr.push(string) )
return console.log(newArr)
}
getStringList(arr)
```
17. Use reduce to sum all the numbers in the numbers array.
```js
// app.js
const numbers = [2,3,4,5,6]
let sum = numbers.reduce((acc,cur) => acc + cur )
console.log(sum)
```
18. Use reduce to concatenate all the countries and to produce this sentence: Estonia, Finland, Sweden, Denmark, Norway, and IceLand are north European countries
```js
// app.js
const ulkeler = ['Estonya', 'Finlandiya', 'İsveç', 'Danimarka', 'Norveç', 'İzlanda'];
// reduce fonksiyonu ile yeni bir string oluşturuyoruz
const cumle = ulkeler.reduce(function(onceki, ulke, indeks, dizi) {
// son elemana gelinceye kadar ülkeleri virgülle ayırıyoruz
if (indeks < dizi.length - 1) {
return onceki + ulke + ', ';
} else {
// son elemana geldiğimizde sonuna nokta ve kuzey Avrupa ülkeleridir ifadesini ekliyoruz
return onceki + ulke + '. kuzey Avrupa ülkeleridir';
}
}, ''); // '' başlangıç değeri
// yeni stringi yazdırıyoruz
console.log(cumle);
// Estonya, Finlandiya, İsveç, Danimarka, Norveç, İzlanda. kuzey Avrupa ülkeleridir
```
19. Explain different between some and every
```js
// app.js
var sayilar = [1, 2, 3, 4, 5];
var sonuc = sayilar.some(function(sayi) {
return sayi > 10; // sayı 10'dan büyükse true, değilse false döndürür
});
console.log(sonuc); // false, çünkü dizideki hiçbir sayı 10'dan büyük değil
var sayilar = [1, 2, 3, 4, 5];
var sonuc = sayilar.every(function(sayi) {
return sayi < 10; // sayı 10'dan küçükse true, değilse false döndürür
});
console.log(sonuc); // true, çünkü dizideki tüm sayılar 10'dan küçük
```
20. Use some to check if some names' length greater than seven in names array
```js
// app.js
const names = ['nevzat','atalay','gül','atalay']
const newArr = names.some((name1) => name1.length > 5)
console.log(newArr)
```
21. Use every to check if all the countries contain the word land
```js
// app.js
const countries = ['Finland', 'Sweden', 'Denmark', 'Norway', 'IceLand']
const newArr = countries.every((count) => count.includes('land') )
console.log(newArr)
```
22. Explain the difference between find and findIndex
```js
// app.js
Find metodu, bir dizide koşulu sağlayan ilk elemanın değerini döndürür. FindIndex metodu ise, bir dizide koşulu sağlayan ilk elemanın indeks numarasını döndürür
```
23. Use find to find the first country containing only six letters in the countries array
```js
// app.js
const countries = ['Finland', 'Sweden', 'Denmark', 'Norway', 'IceLand']
const newArr = countries.find((count) => count.length == 6)
console.log(newArr)
```
24. Use findIndex to find the position of the first country containing only six letters in the countries array
```js
// app.js
const countries = ['Finland', 'Sweden', 'Denmark', 'Norway', 'IceLand']
const newArr = countries.findIndex((count) => count.length == 6)
console.log(newArr)
```
25. Use findIndex to find the position of Norway if it doesn't exist in the array you will get -1.
```js
// app.js
const countries = ['Finland', 'Sweden', 'Denmark', 'Norway', 'IceLand']
const newArr = countries.findIndex((count) => count.includes("Norway"))
console.log(newArr)
```
26. Use findIndex to find the position of Russia if it doesn't exist in the array you will get -1.
```js
// app.js
const countries = ['Finland', 'Sweden', 'Denmark', 'Norway', 'IceLand']
const newArr = countries.findIndex((count) => count.includes("russia"))
console.log(newArr)
```
### Exercises: Level 2
1. Find the total price of products by chaining two or more array iterators(eg. arr.map(callback).filter(callback).reduce(callback))
```js
// app.js
const numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9];
// Filter the odd numbers
const oddNumbers = numbers.filter(number => number % 2 === 1);
// Map the odd numbers to their squares
const squares = oddNumbers.map(number => number ** 2);
// Reduce the squares to get the sum
const sum = squares.reduce((total, square) => total + square, 0);
// Log the result
console.log(sum); // 165
```
2. Find the sum of price of products using only reduce reduce(callback)
```js
//app.js
const products = [
{ product: 'banana', price: 3 },
{ product: 'mango', price: 6 },
{ product: 'potato', price: ' ' },
{ product: 'avocado', price: 8 },
{ product: 'coffee', price: 10 },
{ product: 'tea', price: '' },
];
const sum = products.reduce((previousValue, currentValue) => {
const price = parseFloat(currentValue.price);
if (!isNaN(price)) {
return previousValue + price;
}
return previousValue;
}, 0);
console.log(sum); // Output: 27
```
3. Declare a function called **_categorizeCountries_** which returns an array of countries which have some common pattern(you find the countries array in this repository as countries.js(eg 'land', 'ia', 'island','stan')).
```js
//app.js
const countries = [ 'China', 'Belarus', 'Ireland', 'New Zealand', 'Germany', 'Switzerland', 'Thailand', 'Uzbekistan' ,"Turkey","Rusia"]
function categorizeCountries(patterns) {
return countries.filter(country => {
return patterns.some(pattern => {
return country.toLowerCase().includes(pattern.toLowerCase());
});
});
}
const patterns = ['land', 'ia', 'island', 'stan'];
const result = categorizeCountries(patterns);
console.log(result);
```
4. Create a function which return an array of objects, which is the letter and the number of times the letter use to start with a name of a country.
```js
//app.js
```
5. Declare a **_getFirstTenCountries_** function and return an array of ten countries. Use different functional programming to work on the countries.js array
```js
//app.js
```
6. Declare a **_getLastTenCountries_** function which which returns the last ten countries in the countries array.
```js
//app.js
```
7. Find out which _letter_ is used many _times_ as initial for a country name from the countries array (eg. Finland, Fiji, France etc)
```js
//app.js
```
### Exercises: Level 3
1. Use the countries information, in the data folder. Sort countries by name, by capital, by population
```js
//app.js
```
2. \*\*\* Find the 10 most spoken languages:
````js
// Your output should look like this
console.log(mostSpokenLanguages(countries, 10))
[
{country: 'English',count:91},
{country: 'French',count:45},
{country: 'Arabic',count:25},
{country: 'Spanish',count:24},
{country:'Russian',count:9},
{country:'Portuguese', count:9},
{country:'Dutch',count:8},
{country:'German',count:7},
{country:'Chinese',count:5},
{country:'Swahili',count:4}
]
// Your output should look like this
console.log(mostSpokenLanguages(countries, 3))
[
{country: 'English',count: 91},
{country: 'French',count: 45},
{country: 'Arabic',count: 25},
]```
````
3. \*\*\* Use countries_data.js file create a function which create the ten most populated countries
````js
console.log(mostPopulatedCountries(countries, 10))
[
{country: 'China', population: 1377422166},
{country: 'India', population: 1295210000},
{country: 'United States of America', population: 323947000},
{country: 'Indonesia', population: 258705000},
{country: 'Brazil', population: 206135893},
{country: 'Pakistan', population: 194125062},
{country: 'Nigeria', population: 186988000},
{country: 'Bangladesh', population: 161006790},
{country: 'Russian Federation', population: 146599183},
{country: 'Japan', population: 126960000}
]
console.log(mostPopulatedCountries(countries, 3))
[
{country: 'China', population: 1377422166},
{country: 'India', population: 1295210000},
{country: 'United States of America', population: 323947000}
]
```
````
4. \*\*\* Try to develop a program which calculate measure of central tendency of a sample(mean, median, mode) and measure of variability(range, variance, standard deviation). In addition to those measures find the min, max, count, percentile, and frequency distribution of the sample. You can create an object called statistics and create all the functions which do statistical calculations as method for the statistics object. Check the output below.
```js
const ages = [31, 26, 34, 37, 27, 26, 32, 32, 26, 27, 27, 24, 32, 33, 27, 25, 26, 38, 37, 31, 34, 24, 33, 29, 26]
console.log('Count:', statistics.count()) // 25
console.log('Sum: ', statistics.sum()) // 744
console.log('Min: ', statistics.min()) // 24
console.log('Max: ', statistics.max()) // 38
console.log('Range: ', statistics.range() // 14
console.log('Mean: ', statistics.mean()) // 30
console.log('Median: ',statistics.median()) // 29
console.log('Mode: ', statistics.mode()) // {'mode': 26, 'count': 5}
console.log('Variance: ',statistics.var()) // 17.5
console.log('Standard Deviation: ', statistics.std()) // 4.2
console.log('Variance: ',statistics.var()) // 17.5
console.log('Frequency Distribution: ',statistics.freqDist()) # [(20.0, 26), (16.0, 27), (12.0, 32), (8.0, 37), (8.0, 34), (8.0, 33), (8.0, 31), (8.0, 24), (4.0, 38), (4.0, 29), (4.0, 25)]
```
```sh
console.log(statistics.describe())
Count: 25
Sum: 744
Min: 24
Max: 38
Range: 14
Mean: 30
Median: 29
Mode: (26, 5)
Variance: 17.5
Standard Deviation: 4.2
Frequency Distribution: [(20.0, 26), (16.0, 27), (12.0, 32), (8.0, 37), (8.0, 34), (8.0, 33), (8.0, 31), (8.0, 24), (4.0, 38), (4.0, 29), (4.0, 25)]
```

154
Exercise-Solutions/10_day_sets_and_maps.md
Unescape View File

@ -0,0 +1,154 @@
1. create an empty set
const countries = new Set()
console.log(countries)
2. Create a set containing 0 to 10 using loop
const set = new Set()
set.add(0,)
set.add(1)
set.add(2)
set.add(3)
set.add(4)
set.add(5)
set.add(6)
set.add(7)
set.add(8)
set.add(9)
set.add(10)
console.log(set)
3. Remove an element from a set
const set = new Set()
set.add(0,)
set.add(1)
set.add(2)
console.log(set.delete(1))
4. Clear a set
const set = new Set()
set.add(0,)
set.add(1)
set.add(2)
set.clear()
console.log(set)
5. Create a set of 5 string elements from array
const arr = ['ayşe','fatma','dilan','cansu']
const set = new Set(arr)
console.log(set)
6. Create a map of countries and number of characters of a country
const map = new Map()
map.set(1,'turkey')
map.set(2,'russıa')
map.set(3,'germaby')
console.log(map)
### Exercise Level 2
1. Find a union b
```js
//app.js
const a = [4, 5, 8, 9]
const b = [3, 4, 5, 7]
const c =[ ...a,...b
]
const A = new Set(a)
const B = new Set(b)
const C = new Set(c)
console.log(C)
```
2. Find a intersection b
```js
//app.js
const a = [4, 5, 8, 9]
const b = [3, 4, 5, 7]
const A = new Set(a)
const B = new Set(b)
const aUnionB =a.filter((num) => B.has(num))
console.log(aUnionB)
```
3. Find a with b
```js
//app.js
const a = [4, 5, 8, 9]
const b = [3, 4, 5, 7]
const A = new Set(a)
const B = new Set(b)
const aUnionB =a.filter((num) => !B.has(num))
console.log(aUnionB)
```
### Exercises Level 3
1. How many languages are there in the countries object file.
2. Use the countries data to find the 10 most spoken languages:
```
// Your output should look like this
console.log(mostSpokenLanguages(countries, 10))
[
{ English: 91 },
{ French: 45 },
{ Arabic: 25 },
{ Spanish: 24 },
{ Russian: 9 },
{ Portuguese: 9 },
{ Dutch: 8 },
{ German: 7 },
{ Chinese: 5 },
{ Swahili: 4 },
{ Serbian: 4 }
]
// Your output should look like this
console.log(mostSpokenLanguages(countries, 3))
[
{English:91},
{French:45},
{Arabic:25}
]
```
```js
// app.js
// Your output should look like this
console.log(mostSpokenLanguages(countries, 10))
[
{ English: 91 },
{ French: 45 },
{ Arabic: 25 },
{ Spanish: 24 },
{ Russian: 9 },
{ Portuguese: 9 },
{ Dutch: 8 },
{ German: 7 },
{ Chinese: 5 },
{ Swahili: 4 },
{ Serbian: 4 }
]
// Your output should look like this
console.log(mostSpokenLanguages(countries, 3))
[
{English:91},
{French:45},
{Arabic:25}
]
```
Write Preview
Loading…
Cancel
Save