Today we will start in a quiet way, but with a very important learning to move on to the next few days of challenges!
In case you haven't gone through this yet, it is very common when using Javascript to have problems with the types of variables when assigning new values and comparing them.
Therefore, you will rewrite the code below so that it is printing the information correctly, which makes sense and without errors:
let numberOne = 1
let stringOne = '1'
let numberThirty = 30
let stringThirty = '30'
let numberTen = 10
let stringTen = '10'
if (numberOne = stringOne) {
console.log('The variables numberOne and stringOne have the same value, but different types')
} else {
console.log('The variables numberOne and stringOne do not have the same value')
}
if (numberThirty == stringThirty) {
console.log('The variables numberThirty and stringThirty have the same value and type')
} else {
console.log('The variables numberThirty and stringThirty do not have the same type')
}
if (numberTen === stringTen) {
console.log('Variables numberTen and stringTen have the same value, but different types')
} else {
console.log('Variables numberTen and stringTen do not have the same value')
}You can use the browser itself to run your program if you are not yet familiar with code editors, such as Visual Studio Code
To do this, just right-click on any page, go to console and type your code, very simple
If you want to change the names of variables and values, feel free, but never print something that is not true, huh!
To learn more about comparison operators, take a look at this article
Take the opportunity to also study Javascript in Alura courses
Do you know when you register on a website and soon after, when you log in, it already calls you by your own name? In today's challenge we will do that!
You will need to develop a little program that will simulate one of these sites and it will ask the person who is going to use it to answer 3 questions:
What's your name?
How old are you?
What programming language are you studying?
And, clearly, the person using the program must answer each one as they are made
At the end, the program will print the message:
"Hello X, you are X years old and already learning X!"
Where each X is one of the answers given by the person
You can add as many questions as you want, including adding the person's answers in the message that will be printed
To print and receive values, you can either use console.log, prompt and alert, or use HTML and CSS if you already know these two technologies
To learn more about prompt and alert, take a look at this site
Take the opportunity to also study Javascript in Alura courses
Have you ever played a game where he gave you more than one choice and depending on which one you chose, the character's fate would be totally different?
Let's do an example with Javascript!
Your challenge today is to create the possible destinations of a game, in which the player can choose:
-
At the beginning of your studies, where you can choose between go to the front-end area or go to the back-end area
-
In the middle, where if she is in the front-end area, she can keep learning React or keep learning Vue and, if she is in the back area -end, you can keep learning C# or keep learning Java
-
At the end, where, regardless of her previous choices, she will be able to choose between continue specializing in the chosen area or continue developing to become a fullstack
The important thing is that the person who plays can always choose which decision to make to be able to learn and develop in the programming area
You can already have an idea of how to make this whole story happen, right? Especially remembering how we use conditional structures in Javascript!
If you still don't know how to print and receive values on web pages with HTML and CSS, you can use console.log, prompt and alert to develop your game
Remember you can always customize the game however you want!
To learn more about conditional frameworks in Javascript, take a look at this site
Take the opportunity to also study Javascript in Alura courses
Have you ever played trying to guess the number your friend was thinking of? Because today you will play this game against the computer itself!
Here's everything you need to do for today's challenge:
You must create a little program that already initializes with a specific value between 0-10 for the number you are going to guess Then he'll ask you what value do you want to guess and, if you get it right, he'll congratulate you or, if you're wrong, he'll give you 2 more tries In the end, if you don't get it right, it will print what the initial number was
Think carefully about which repetition structure you will use to make your program run until the 3 attempts are over or the person hits the number
Remember that you can always customize your little program however you want!
You can even increment your program and make the machine itself choose the number to guess, using something called Math.random(), which you can check [on this site](https://developer.mozilla.org/ en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/random)
To learn more about looping structures, take a look at this site
Take the opportunity to also study Javascript in Alura courses
Have you ever gone to the supermarket and taken a shopping list, but as you wrote everything down in the order you remembered, you had to get an apple in the fruit area, then a milk in the dairy area and then a pear again in the fruit area and stayed in this back and forth all over the place to complete the list?
Once you solve today's challenge, you definitely won't be doing that anymore!
What should you do then:
To facilitate your trip to the supermarket, you will create a program in Javascript, where it will ask if you want to add a food to the shopping list for you to answer with yes or no.
Then it will ask you which food you want to insert and you will type its name, such as potato.
Then, he should ask which category this food fits in, with pre-defined options, such as dairy, frozen, sweets and whatever else he finds interesting, so he can separate everything in its proper place. group
Finally, if you no longer want to add anything to the shopping list and answer no to the first question, it will print a list with all items grouped, as follows:
If you add to your list:
banana, milk powder, tomato, vegetable milk, gum, bear candy, apple, grape, avocado and cow's milk
The program should print, for example:
`Shopping list: banana, tomato, apple, grape, avocado, powdered milk, plant-based milk, cow's milk, gum and teddy bear'
We have an object within the javascript language that is used precisely to create lists of elements, called array. Use and abuse it!
Remember that you can always style your little program the way you want, including using other technologies for this, such as HTML and CSS. But this is not mandatory on our list of Javascript programming logic, so as I mentioned in previous days, you can use resources like console.log, alert and prompt to develop your program
To learn more about arrays in Javascript, take a look at this site
Also don't forget to concatenate the different lists of categories into one at the end, for that you can read [this site](https://developer.mozilla.org/pt-BR/docs/Learn/JavaScript/First_steps/ Strings)
Take the opportunity to also study Javascript in Alura courses
Remember yesterday, when we created a little program to create our own shopping list? Well, today our challenge is to make it even cooler!
You must create the option to delete an item from the list, which will be displayed next to the question of do you want to add a food to the shopping list? From there, the program will print the elements present in the current list and the person will have to write which one he wants to remove After that, the program will delete the element from the list and print confirmation that the item really isn't there anymore Finally, it will go back to its initial question cycle
Remember that the option to delete an item should only be available from the moment there is at least one element in the shopping list
You can search for the element that the person wants to delete the way you want, using Javascript methods for this or manually writing everything that will happen
Don't forget to always customize your little program the way you see fit!
To learn more about methods for arrays in Javascript, take a look at this site
Take the opportunity to also study Javascript in Alura courses
That was quite a week, right? We practice a lot about programming logic with Javascript, but there is still one very important thing missing: organize our code
And yes, this is something mandatory to learn as a developer, because at one time or another in your career you will need to maintain your created code, or even fix something in the code that someone else wrote. Just imagine if this code is all messed up?
A good practice is to always separate each snippet of your code that will perform some specific function into even smaller blocks of code, but which can be reused and called at any other time throughout your program. These are called functions
Have you ever stopped to think about how a calculator works?
It asks you to enter a number, then you select a type of operation with another number and it does the calculation itself to show you the result! Amazing right?
And then our last challenge will be to create our own calculator, but with a very important detail: each operation must be a different function in our code
The person must choose an operation option printed by the program on the screen, then he/she must insert the two values he/she wants to use and the program must print the result
The available options should be: sum, multiplication, division, subtraction and exit, and in the latter the program should stop executing, showing a message "until next time"
Each operation must be a different function in our code, which will receive the values entered as parameters and return the result of the operation
Don't forget to use repeat structures to make the calculator print the choice of operation until the person wants to stop the program
Also remember that in addition to if and else we also have the switch, very interesting to use in cases like this, multiple choice
Customize your calculator however you like!
To learn more about functions in Javascript, take a look at this site
If you haven't studied switch yet, check out this site
Take the opportunity to also study Javascript in Alura courses