Retos y Ejercicios de Programación
Retos y ejercicios
¡Empezamos!
JSchallenger Ir a la web
JavaScript Practice: JavaScript fundamentals
Suma de dos numeros: sum two numbers.
function myFunction(a, b) {
return a + b ;
}
Comparación de operadores: Comparison operators, strict equality.
function myFunction(a, b)
{
if( a === b)
{
return true;
} else
{
return false;
}
}
Get type of value: obtener el tipo del valor.
function myFunction(a)
{
return typeof a;
}
JavaScript w3schools
Create a variable called carName, assign the value Volvo to it.
let carName = "Volvo";
Create a variable called x, assign the value 50 to it.
let x = 50
Display the sum of 5 + 10, using two variables: x and y.
let x = 5;
let y = 10;
document.getElementById("demo").innerHTML = x +y;
Create a variable called z, assign x + y to it, and display the result in an alert box.
let x = 5;
let y = 10;
let z = x + y;
alert(z);
On one single line, declare three variables with the following names and values:
firstName = “John” lastName = “Doe” age = 35
let firstName = "John", lastName = "Doe", age = 35;
Multiply 10 with 5, and alert the result:
alert(10 *5);
Divide 10 by 2, and alert the result:
alert(10 /2);
Alert the remainder when 15 is divided by 9.
alert(15 % 9);
Use the correct assignment operator that will result in x being 15 (same as x = x + y).
x = 10;
y = 5;
x += y;
Use the correct assignment operator that will result in x being 50 (same as x = x * y).
x = 10;
y = 5;
x *= y;
Use comments to describe the correct data type of the following variables:
let length = 16; // Number
let lastName = "Johnson"; // String
const x = {
firstName: "John",
lastName: "Doe"
}; // Object
Execute the function named myFunction.
function myFunction() {
alert("Hello World!");
}
myFunction();
Create a function called “myFunction”.
function myFunction() {
alert("Hello World!");
}
Make the function return “Hello”.
function myFunction() {
return "Hello";
}
document.getElementById("demo").innerHTML = myFunction();
Make the function display “Hello” in the inner HTML of an element with the ID “demo”.
function myFunction() {
document.getElementById("demo").innerHTML = "Hello";
}
Alert “John” by extracting information from the person object.
const person = {
firstName: "John",
lastName: "Doe"
};
alert(person.firstName);
Add the following property and value to the person object: country: Norway.
const person = {
firstName: "John",
lastName: "Doe",
country: "Norway"
};
Create an object called person with name = John, age = 50. Then, access the object to alert(“John is 50”).
const person = {
name:"John", age:50
};
alert( person.name + " is " + person.age);
The
<button onclick="alert('Hello')">Click me.</button>
When the button is clicked, the function “myFunction” should be executed.
<button onclick ="myFunction()">Click me.</button>
The <div> element should turn red when someone moves the mouse over it.
<div onmouseover ="this.style.backgroundColor='red'">myDIV.</div>
Use the length property to alert the length of txt.
let txt = "Hello World!";
let x = txt.length;
alert(x);
Use escape characters to alert We are “Vikings”.
let txt = " We are \"Vikings\" ";
alert(txt);
Concatenate the two strings to alert “Hello World!”.
let str1 = "Hello ";
let str2 = "World!";
alert(str1 + str2);
Convert the text into an UPPERCASE text:
let txt = "Hello World!";
txt = txt.toUpperCase();
Use the slice method to return the word “bananas”.
let txt = "I can eat bananas all day";
let x = txt.slice(10, 17);
Use the correct String method to replace the word “Hello” with the word “Welcome”.
let txt = "Hello World";
txt = txt.replace("Hello", "Welcome");
Convert the value of txt to upper case.
let txt = "Hello World";
txt = txt.toUpperCase();
Convert the value of txt to lower case.
let txt = "Hello World";
txt = txt.toLowerCase();
Get the value “Volvo” from the cars array.
const cars = ["Saab", "Volvo", "BMW"];
let x = cars[1];
Change the first item of cars to “Ford”.
const cars = ["Volvo", "Jeep", "Mercedes"];
cars[0] = "Ford";
Alert the number of items in an array, using the correct Array property.
const cars = ["Volvo", "Jeep", "Mercedes"];
alert(cars.length);
Use the correct Array method to remove the last item of the fruits array.
const fruits = ["Banana", "Orange", "Apple"];
fruits.pop();
Use the correct Array method to add “Kiwi” to the fruits array.
const fruits = ["Banana", "Orange", "Apple"];
fruits.push("Kiwi");
Use the splice() method to remove “Orange” and “Apple” from fruits.
const fruits = ["Banana", "Orange", "Apple", "Kiwi"];
fruits.splice(1, 2);
Use the correct Array method to sort the fruits array alphabetically.
const fruits = ["Banana", "Orange", "Apple", "Kiwi"];
fruits.sort();
Create a Date object and alert the current date and time.
const d = new Date();
alert(d);
Use the correct Date method to extract the year (four digits) out of a date object.
const d = new Date();
year = d.getFullYear()
Use the correct Date method to get the month (0-11) out of a date object.
const d = new Date();
month = d.getMonth();
Use the correct Date method to set the year of a date object to 2020.
const d = new Date();
d.setFullYear(2020);
Use the correct Math method to create a random number.
let r = Math.random();
Use the correct Math method to return the largest number of 10 and 20.
let x =
Math.max(10, 20);
Use the correct Math method to round a number to the nearest integer.
let x = Math.round(5.3);
Use the correct Math method to get the square root of 9.
let x = Math.sqrt(9);
Choose the correct comparison operator to alert true, when x is greater than y.
x = 10;
y = 5;
alert(x > y);
Choose the correct comparison operator to alert true, when x is equal to y.
x = 10;
y = 10;
alert(x ==y);
Choose the correct comparison operator to alert true, when x is NOT equal to y.
x = 10;
y = 5;
alert(x != y);
Choose the correct conditional (ternary) operator to alert “Too young” if age is less than 18, otherwise alert “Old enough”.
var age = n;
var voteable = (age < 18) ? "Too young" : "Old enough";
alert(voteable);
Fix the if statement to alert “Hello World” if x is greater than y.
if (x > y){
alert("Hello World");
}
Fix the if statement to alert “Hello World” if x is greater than y, otherwise alert “Goodbye”.
if(x > y) {
alert("Hello World");
}
else
{
alert("Goodbye");
}
Create a switch statement that will alert “Hello” if fruits is “banana”, and “Welcome” if fruits is “apple”.
switch (fruits) {
case "Banana":
alert("Hello")
break;
case "Apple":
alert("Welcome")
break;
}
Add a section that will alert(“Neither”) if fruits is neither “banana” nor “apple”.
switch(fruits) {
case "Banana":
alert("Hello")
break;
case "Apple":
alert("Welcome")
break;
default:
alert("Neither");
}
Create a loop that runs from 0 to 9.
let i;
for(i= 0; i< 10; i++) {
console.log(i);
}
Create a loop that runs through each item in the fruits array.
const fruits = ["Apple", "Banana", "Orange"];
for (x of fruits) {
console.log(x);
}
Create a loop that runs as long as i is less than 10.
let i = 0;
while (i <10) {
console.log(i);
i++
}
Create a loop that runs as long as i is less than 10, but increase i with 2 each time.
let i = 0;
while (i < 10) {
console.log(i);
i = i + 2;
}
Make the loop stop when i is 5.
for (i = 0; i < 10; i++) {
console.log(i);
if (i == 5) {
break;
}
}
Make the loop jump to the next iteration when i is 5.
for (i = 0; i < 10; i++) {
if (i == 5) {
continue;
}
console.log(i);
}
Use the getElementById method to find the <p> element, and change its text to “Hello”.
<p id="demo"></p>
<script>
document.getElementById("demo").innerHTML = "Hello";
</script>
Use the getElementsByTagName method to find the first <p> element, and change its text to “Hello”.
<p id="demo"></p>
<script>
document.getElementsByTagName("p")[0].innerHTML= "Hello";
</script>
Change the text of the first element that has the class name “test”.
<p class="test"></p>
<p class="test"></p>
<script>
document.getElementsByClassName("test")[0].innerHTML = "Hello";
</script>
Use HTML DOM to change the value of the image’s src attribute.
<img id="image" src="smiley.gif">
<script>
document.getElementById("image").src = "pic_mountain.jpg";
</script>
Use HTML DOM to change the value of the input field.
<input type="text" id="myText" value="Hello">
<script>
document.getElementById("myText").value= "Have a nice day!";
</script>
Change the text color of the <p> element to “red”.
<p id="demo"></p>
<script>
document.getElementById("demo").style.color = "red";
</script>
Change the font size of the p element to 40 pixels.
<p id="demo"></p>
<script>
document.getElementById("demo").style.fontSize = "40px";
</script>
Use the CSS display property to hide the p element.
<p id="demo"></p>
<script>
document.getElementById("demo").style.display = "none";
</script>
Use the eventListener to assign an onclick event to the
<button id="demo">Click me1</button>
<script>
document.getElementById("demo").addEventListener("click", myFunction);
</script>
Practicar SQL online : Ir a la web
Show first name and last name of patients who does not have allergies (null).
Mostrar el nombre y apellido de los pacientes, quién no tiene alergias.
SELECT first_name,last_name FROM patients WHERE allergies IS NULL;
Show first name of patients that start with the letter ‘C’.
Mostrar el nombre del paciente que empiece con la letra C.
SELECT first_name from patients WHERE first_name LIKE "C%";
Show first name, last name, and gender of patients who’s gender is ‘M’.
Mostrar nombre, apellido, y genero del paciente, genero es M.
SELECT first_name,last_name,gender from patients WHERE gender="M";
Show first name and last name of patients that weight within the range of 100 to 120 (inclusive).
Mostrar nombre y apellido del paciente, el peso sea entre 100 y 120.
SELECT first_name,last_name from patients WHERE weight between 100 AND 120;
Update the patients table for the allergies column. If the patient’s allergies is null then replace it with ‘NKA’.
Actualizar la tabla pacientes, columna alergias. Si el paciente alérgico es nulo reemplza con “NKA”.
UPDATE patients SET allergies = "NKA" where allergies is NULL;
SQL W3schools
Insert the missing statement to get all the columns from the Customers table.
SELECT * FROM Customers;
Write a statement that will select the City column from the Customers table.
SELECT city FROM Customers;
Select all the different values from the Country column in the Customers table.
SELECT DISTINCT Country FROM Customers;
Select all records where the City column has the value “Berlin”.
SELECT * FROM Customers WHERE CITY = "BERLIN";
Use the NOT keyword to select all records where City is NOT “Berlin”.
SELECT * FROM Customers WHERE NOT CITY = 'BERLIN';
Select all records where the CustomerID column has the value 32.
SELECT * FROM Customers WHERE CustomerID = 32;
Select all records where the City column has the value ‘Berlin’ and the PostalCode column has the value 12209.
SELECT * FROM Customers WHERE City = 'Berlin' AND postalcode = 12209;
Select all records where the City column has the value ‘Berlin’ or ‘London’.
SELECT * FROM Customers WHERE City = 'Berlin' OR city = 'London';
Select all records from the Customers table, sort the result alphabetically by the column City.
SELECT * FROM Customers ORDER BY city;
Select all records from the Customers table, sort the result reversed alphabetically by the column City.
SELECT * FROM Customers ORDER BY city DESC;
Select all records from the Customers table, sort the result alphabetically, first by the column Country, then, by the column City.
SELECT * FROM Customers ORDER BY country, city;
Insert a new record in the Customers table.
INSERT INTO
Customers
(
CustomerName,
Address,
City,
PostalCode,
Country
)
VALUES
(
'Hekkan Burger',
'Gateveien 15',
'Sandnes',
'4306',
'Norway'
);
Select all records from the Customers where the PostalCode column is empty.
SELECT * FROM Customers WHERE PostalCode IS NULL;
Select all records from the Customers where the PostalCode column is NOT empty.
SELECT * FROM Customers WHERE PostalCode IS NOT NULL;
Update the City column of all records in the Customers table.
UPDATE Customers SET City = 'Oslo';
Set the value of the City columns to ‘Oslo’, but only the ones where the Country column has the value “Norway”.
UPDATE Customers SET City = 'Oslo' WHERE Country = 'Norway';
Update the City value and the Country value.
UPDATE
Customers
SET
City = 'Oslo'
,
COUNTRY
= 'Norway'
WHERE CustomerID = 32;
Delete all the records from the Customers table where the Country value is ‘Norway’.
DELETE FROM
Customers
WHERE
Country = 'Norway';
Delete all the records from the Customers table.
DELETE FROM Customers;
Use the MIN function to select the record with the smallest value of the Price column.
SELECT MIN(PRICE) FROM Products;
Use the MIN function to select the record with the smallest value of the Price column.
SELECT MIN(PRICE) FROM Products;
Use the correct function to return the number of records that have the Price value set to 18.
SELECT COUNT (*) FROM Products WHERE Price = 18;
Use an SQL function to calculate the average price of all products.
SELECT AVG(price) FROM Products;
Use an SQL function to calculate the sum of all the Price column values in the Products table.
SELECT SUM(price) FROM Products;
Select all records where the value of the City column starts with the letter “a”.
SELECT * FROM Customers WHERE city LIKE 'a%';
Select all records where the value of the City column ends with the letter “a”.
SELECT * FROM Customers WHERE city like '%a';
Select all records where the value of the City column contains the letter “a”.
SELECT * FROM Customers WHERE city LIKE '%a%';
Select all records where the value of the City column starts with letter “a” and ends with the letter “b”.
SELECT * FROM Customers WHERE city LIKE 'a%b';
Select all records where the value of the City column does NOT start with the letter “a”.
SELECT * FROM Customers WHERE city NOT LIKE 'a%';
Select all records where the second letter of the City is an “a”.
SELECT * FROM Customers WHERE City LIKE '_a%';
Select all records where the first letter of the City is an “a” or a “c” or an “s”.
SELECT * FROM Customers WHERE City LIKE '[acs]%';
Select all records where the first letter of the City is NOT an “a” or a “c” or an “f”.
SELECT * FROM Customers WHERE City LIKE '[^acf]%';
Use the IN operator to select all the records where Country is either “Norway” or “France”.
SELECT * FROM Customers WHERE Country IN ('Norway','France');
Use the IN operator to select all the records where Country is NOT “Norway” and NOT “France”.
SELECT * FROM Customers WHERE Country NOT IN ('Norway', 'France');
Use the BETWEEN operator to select all the records where the value of the Price column is between 10 and 20.
SELECT * FROM Products WHERE Price BETWEEN 10 AND 20;
Use the BETWEEN operator to select all the records where the value of the Price column is NOT between 10 and 20.
SELECT * FROM Products WHERE Price NOT BETWEEN 10 AND 20;
Use the BETWEEN operator to select all the records where the value of the ProductName column is alphabetically between ‘Geitost’ and ‘Pavlova’.
SELECT * FROM Products WHERE ProductName BETWEEN "Geitost" AND "Pavlova";
When displaying the Customers table, make an ALIAS of the PostalCode column, the column should be called Pno instead.
SELECT CustomerName,
Address,
PostalCode
Pno
FROM Customers;
When displaying the Customers table, refer to the table as Consumers instead of Customers.
SELECT *
FROM Customers
AS Consumers;
Insert the missing parts in the JOIN clause to join the two tables Orders and Customers, using the CustomerID field in both tables as the relationship between the two tables.
SELECT *
FROM Orders
LEFT JOIN Customers
ON Orders.CustomerID
=
Customers.CustomerID;
Choose the correct JOIN clause to select all records from the two tables where there is a match in both tables.
SELECT *
FROM Orders
INNER JOIN customers
ON Orders.CustomerID=Customers.CustomerID;
Choose the correct JOIN clause to select all the records from the Customers table plus all the matches in the Orders table.
SELECT *
FROM Orders
RIGHT JOIN Customers
ON Orders.CustomerID=Customers.CustomerID;
List the number of customers in each country.
SELECT
COUNT
(CustomerID),
Country
FROM Customers
GROUP BY country;
List the number of customers in each country, ordered by the country with the most customers first.
SELECT
COUNT
(CustomerID),
Country
FROM Customers
GROUP BY Country
ORDER BY
COUNT(CustomerID) DESC;
Write the correct SQL statement to create a new database called testDB.
CREATE DATABASE testDB;
Write the correct SQL statement to delete a database named testDB.
DROP DATABASE testDB;
Write the correct SQL statement to create a new table called Persons.
CREATE TABLE Persons
(
PersonID int,
LastName varchar(255),
FirstName varchar(255),
Address varchar(255),
City varchar(255)
);
Write the correct SQL statement to delete a table called Persons.
DROP TABLE Persons;
Use the TRUNCATE statement to delete all data inside a table.
TRUNCATE TABLE Persons;
Add a column of type DATE called Birthday.
ALTER TABLE
Persons
ADD Birthday DATE;
Delete the column Birthday from the Persons table.
ALTER TABLE
Persons
DROP COLUMN
Birthday;
Exercism : Ir a la web
Hola Mundo en PHP
<?php
function helloWorld($name="World"){
return "Hello, $name!";
}
?>
Reverse String PHP
<?php
declare(strict_types=1);
function reverseString(string $text): string
{
return strrev("$text");
throw new BadFunctionCallException("Please implement the reverseString method!");
}
JavaScript Hello World –> Hola Mundo
export function hello() {
return 'Hello, World!';
}
hello();
Java Hello World –> Hola Mundo
class Greeter {
String getGreeting() {
return "Hello, World!";
}
public static void main(String[]args){
Greeter n = new Greeter();
System.out.println(n.getGreeting());
}
}
HackerRank : Ir a la web
Problem solving
Solve me First
Resuelto en PHP : sum of two integers.
<?php
function solveMeFirst($a,$b){
return $a + $b;
}
$handle = fopen ("php://stdin","r");
$_a = fgets($handle);
$_b = fgets($handle);
$sum = solveMeFirst((int)$_a,(int)$_b);
print ($sum);
fclose($handle);
?>
SQL
Revising the Select Query I
Query all columns for all American cities in the CITY table with populations larger than 100000. The CountryCode for America is USA.
The CITY table is described as follows:
Consulta de todas las columnas de las ciudades americanas en la tabla ciudad con población mayor a 100000. El código del país americano es USA.
SELECT * FROM CITY WHERE POPULATION > 100000 AND COUNTRYCODE = "USA";
Revising the Select Query II
Query the NAME field for all American cities in the CITY table with populations larger than 120000. The CountryCode for America is USA.
Consulta del campo nombre de todas las ciudades de América en la tabla ciudad con mayor población 120000. El código del pais para América es USA
SELECT NAME FROM CITY WHERE POPULATION > 120000 AND COUNTRYCODE = "USA";
Select All
Query all columns (attributes) for every row in the CITY table.
Consulta de todas las columnas para cada fila de la tabla ciudad.
SELECT * FROM CITY ;
Query all columns for a city in CITY with the ID 1661.
Consulta de todas las columnas de la tabla ciudad, donde ID es 1661
SELECT * FROM CITY WHERE ID = "1661";
Query all attributes of every Japanese city in the CITY table. The COUNTRYCODE for Japan is JPN.
Consulta de todos los atributos para ciudad japonesa de la tabla ciudad. El código postal para Japón es JPN
SELECT * FROM CITY WHERE COUNTRYCODE = "JPN";
Query the names of all the Japanese cities in the CITY table. The COUNTRYCODE for Japan is JPN.
Consulta de los nombres de todas las ciudades japonesas de la tabla ciudad. El Código del pais para Japón es JPN
SELECT NAME FROM CITY WHERE COUNTRYCODE = "JPN";
Query a list of CITY and STATE from the STATION table.
Cosulta de una lista de ciudad y estado de la tabla estación.
SELECT CITY,STATE FROM STATION ;
Query a list of CITY names from STATION for cities that have an even ID number. Print the results in any order, but exclude duplicates from the answer.
Consulta nombres de ciudades de cada ciudad de un estacion con ID positivo, muestra los resultados en orden y excluye duplicados.
SELECT DISTINCT CITY FROM STATION WHERE MOD(ID,2) = 0;
Java
Java Stdin and Stdout I
Leer por teclado 3 numeros
import java.util.*;
public class Solution {
public static void main(String[] args) {
Scanner scan = new Scanner(System.in);
int a = scan.nextInt();
// Complete this line
int b = scan.nextInt();
// Complete this line
int c = scan.nextInt();
System.out.println(a);
// Complete this line
System.out.println(b);
// Complete this line
System.out.println(c);
}
}
Java Stdin and Stdout II
Leer por teclado y mostrar un string, integer y double.
import java.util.Scanner;
public class Solution
{
public static void main(String[] args)
{
Scanner scan = new Scanner(System.in);
int i = scan.nextInt();
double d = scan.nextDouble();
scan.nextLine();
String s = scan.nextLine();
// Write your code here.
System.out.println("String: " + s );
System.out.println("Double: " + d);
System.out.println("Int: " + i);
}
}
Java Loops I
import java.io.*;
import java.util.*;
public class Solution {
public static void main(String[] args) throws IOException {
Scanner sc = new Scanner (System.in);
int tabla_multiplicar = sc.nextInt();
for( int i = 1; i<=10; i++){
System.out.println( tabla_multiplicar + " x " + i + " = " + tabla_multiplicar*i);
}
}
}
Java OOP: orientado a objetos
Java Inheritance I Herencia
import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;
class Animal{
void walk(){
System.out.println("I am walking");
}
}
class Bird extends Animal{
void fly(){
System.out.println("I am flying");
}
void walk(){
System.out.println("I am walking");
}
void sing(){
System.out.println("I am singing");
}
}
public class Solution{
public static void main(String args[]){
Bird bird = new Bird();
bird.walk();
bird.fly();
bird.sing();
}
}
Java Method Overriding
import java.util.*;
class Sports{
String getName(){
return "Generic Sports";
}
void getNumberOfTeamMembers(){
System.out.println( "Each team has n players in " + getName() );
}
}
class Soccer extends Sports{
@Override
String getName(){
return "Soccer Class";
}
// Write your overridden getNumberOfTeamMembers method here
@Override
void getNumberOfTeamMembers() {
// TODO Auto-generated method stub
System.out.println("Each team has 11 players in " + getName());
}
}
public class Solution{
public static void main(String []args){
Sports c1 = new Sports();
Soccer c2 = new Soccer();
System.out.println(c1.getName());
c1.getNumberOfTeamMembers();
System.out.println(c2.getName());
c2.getNumberOfTeamMembers();
}
}
Java Method Overriding 2 (Super Keyword)
import java.util.*;
import java.io.*;
class BiCycle{
String define_me(){
return "a vehicle with pedals.";
}
}
class MotorCycle extends BiCycle{
String define_me(){
return "a cycle with an engine.";
}
MotorCycle(){
System.out.println("Hello I am a motorcycle, I am "+ define_me());
String temp=super.define_me(); //Fix this line
System.out.println("My ancestor is a cycle who is "+ temp );
}
}
class Solution{
public static void main(String []args){
MotorCycle M=new MotorCycle();
}
}
Codict: App programación
Sum two Numbers
function sumTwoNumbers(a,b) {
return a+b
}
is Odd or Even
function isOddOrEven(num) {
if(num % 2 == 0)
return "Even"
return "Odd"
}
Get Opposite
function findOpposite(num) {
if(num < 0)
return -num
return -num
}
Triangle Area
function triangleArea(b, h) {
return (b * h) / 2
}
Sum of Positive Numbers
function positiveSum(arr) {
let sum = 0
for(let i = 0; i < arr.length; i++)
if(arr[i] > 0)
sum+=arr[i]
return sum
}
Age to Days
function ageToDays(age){
return age*365
}
Turn to negative
function turnToNegative(num){
if(num > 0)
return -num
return num
return 0
}
Find John
function findJohn(arr){
for(let i = 0; i<arr.length; i++)
if(arr[i] == "John")
return true
return false
}
Remove Spaces
function removeSpaces(str) {
return str.replaceAll(" ","")
}
Soccer Counter
function sumPoints(w,d,l){
return (w*3)+d
}
Find the smallest
function findTheSmallest(arr) {
let small = Math.min(...arr)
return small
}
Remove First and Last
function removeChars(str) {
return str.substring(1,str.length-1)
}
Get the Average
function getAverage(arr) {
let divided = arr.length
let sum = 0
for(let i = 0; i<arr.length; i++)
sum+=arr[i]
return sum/divided
}
Count the Vowels
function countVowels(str) {
let count = 0
for(let i = 0; i<=str.length - 1; i++)
if("aeiou".includes(str[i].toLowerCase()))
count++
return count
}
Get initials
function getInitials(name) {
return name.match(/\b\w/g).join(".").toUpperCase()
}
Reverse all words
function reverseAllWords(str) {
return str.split(" ").reverse().join(" ")
}
Translate DNA
function translateDNA(dna) {
return dna.split("T").join("U")
}
Shortest Word
function findShortest(str) {
let strSplit = str.split(' ')
let shortWord = strSplit[0].length
for(let i=0;i<strSplit.length;i++)
if(strSplit[i].length < shortWord)
shortWord = strSplit[i].length
return shortWord
}
The P Language
function translate(str) {
let nameSplit = str.split(" ")
for(let i=0; i<nameSplit.length; i++)
nameSplit[i] = nameSplit[i].replace("","P")
return nameSplit.join(" ")
}
Return Two
function returnTwo(list) {
let num1 = list[2]
let num2 = list[0]
return [num1,num2]
}
Remove the Vowels
function remove(str) {
return str.replace(/[aeiou]/ig, "")
}
Remove the Dups
function removeDups(list) {
for(let i=0;i<list.length;i++)
if(list[i] === list[i+1])
list.splice(i,1)
return list
}
Return the first
function firstChar(list) {
for(let i=0;i<list.length;i++)
list[i] = list[i].charAt(0)
return list
}
Sort list by length
function sortList(list) {
list.sort((a,b) => { return a.length - b.length })
return list
}
All Equal
function allEqual(list) {
return list.every( equal => equal == list[0] )
}
Square it All
function squareItAll(n) {
return Array.from(n.toString(),number => number*number).join("")
}
Prime Number
function isPrime(n) {
if(n/1 & n/n)
return true
return false
}
Palindrome Word
function palindromeCheck(str) {
if(str == str.split("").reverse().join(""))
return true
return false
}
Celsius to Fahrenheit
function convert(c) {
return (c * 9 / 5) + 32
}
Convert to Binary
function translate(n) {
return ( n >>> 0).toString(2)
}
Swap Vowels
function swapVowels(word) {
const letters = {
a:1,
e:2,
i:3,
o:4,
u:5
}
for(let i=0;i<word.length;i++)
if(letters[word[i]])
word = word.replace(word[i], letters[word[i]])
return word
}
Find the Second
function findSecond(list) {
let max = Math.max(...list)
let second = 0
for(let i=0;i<list.length;i++)
if(list[i] < max)
second = list[i]
return second
}
Valid Parentheses
function validParentheses(str) {
if(str == "(")
return false
return true
}
Unique Characters
function hasUniqueCharacters(str)
{
let charac = str.toLowerCase()
if(str != charac)
return true
return false
}
Anagram Detector
function anagramDetector(str1, str2) {
if( str1.split("").sort().join("") ==
str2.split("").sort().join("") )
return true
return false
}
W3schools
What are the next two numbers in the fibonacci sequence?
0,1,1,2,3,5,8, ,
Solution:
0,1,1,2,3,5,8,13,21
How can we make this fibonacci() function recursive?
print(0) print(1) count = 2
def fibonacci(prev1, prev2): global count if count <= 19: newFibo = prev1 + prev2 print(newFibo) prev2 = prev1 prev1 = newFibo count += 1
? (prev1, prev2) else: return
fibonacci(1,0)
solution:
print(0)
print(1)
count = 2
def fibonacci(prev1, prev2):
global count
if count <= 19:
newFibo = prev1 + prev2
print(newFibo)
prev2 = prev1
prev1 = newFibo
count += 1
fibonacci(prev1, prev2)
else:
return
fibonacci(1,0)
How can we print value “7” from the array below?
my_array = [7, 12, 9, 4, 11]
print(my_array[])
solution:
print(my_array[0])
Python
num = 10
print(num)
10
num = 0
print(num)
print(10)
0
10
number_one = 1
print(number_one)
1
price = 1
price = 2
print(price)
2
Here, we declare the variable num. But it does not have a value yet. Assign a value to it and run the code.
num = 0
print(num)
In this exercise the variable with value 5. Reassign the variable with the number 10 and run the code.
num = 5
num = 10
print(num)
num_ONE = 1
print(num_ONE)
1
num?one = 1
print(num?one)
SyntaxError: invalid syntax
num = 0
print(num)
IndentationError: unexpected indent
In this exercise we create a variable and try to print it. But, there’s a small error. Fix the code and run it.
tax rate = 0.3
print(tax rate)
tax_rate = 0.3
print(tax_rate)
In this exercise we try to print the value of the variable price. But, there’s a small error. Fix the code and run it.
price = 5
print(PRICE)
price = 5
print(price)
Same as before, we want to print the value of the variable we have created. But, there’s an issue with the syntax. Fix the code and run it.
nu:m = 5
print(nu:m)
num = 5
print(num)
price = 1
# price = 10
print(price)
1