How to use the loop for(for) in Portugol?

Question

I am learning algorithm, but I was in doubt about the use of Loop para (for). I know it’s a silly question, but unfortunately I have little internet access. I have the book but the doubt is this!

Answer 1

The "to" loop is one of the forms of conditional deviation, that is, test whether a particular condition is met, and depending on the outcome, divert to a different instruction or proceed to the next one. It is composed of four parts:

para ( iniciação ; condição ; passo )
    corpo
fimpara

próxima instrução

1. To iniciação is simply a code that runs before starting the loop; depending on the language, any variable defined there will only exist within the code of that loop. In others, it continues to exist outside of him.

2. To condição It’s a test to see if you should continue inside the loop or get out of it. Typically it is tested after initiation, so that if not satisfied it exits the loop immediately - without executing the corpo and the passo not once - and go to the next instruction.

   If the condition is true, he executes the corpo, then the passo, and then test the condition again, to see if it remains true. If it continues, repeat this step again and again. Only when the condition becomes false does it come out of the loop, going to the next instruction after it.

3. The corpo is the main chunk of code, which will be repeated zero or more times. It has access to the variables of the iniciação and condição, and can manipulate them or not. It can also execute commands that "force" the loop break (break) or continue from the passo (continue) before reaching the end of the corpo. If these commands are not used, the body goes to the end, before moving to the next step.

4. The passo is simply a small code that runs after the corpo, but before testing again condição. In general, its function is to manipulate the variable(s) that composes(m) a condição, so as to give you the chance to get out of the loop.

A complete example would be:

para ( seja i igual a 1 ; enquanto i for menor ou igual a 10 ; incremente i em 1 )
    imprima i vezes i, enter
fimpara
imprima "Fim"

Exit:

1
4
9
16
25
36
49
64
81
100
Fim

All parts, except the condition, are optional. If you omit the iniciação and the passo, the result is the same as a loop enquanto (while):

para ( ; teste() ; )
    faça algo()
fimpara

enquanto ( teste() )
    faça algo()
fimenquanto

The most common syntax for the "for" loop is that of the C family (includes Java, Javascript and others):

for ( int i = 1 ; i <= 10 ; i++ ) {
    printf("%d\n", i*i);
}

Some languages, such as Python and Ruby, do not have this loop, only one with a similar name - the for..in, used to traverse the elements of a list (real or abstract). Often these links are referred to as simply for, but its construction is different.

In English, the "to" loop with a single variable looks something like this (I’m not sure of the exact syntax):

para ( i de 1 a 10 passo 1 ) faca
    escreva(i*i)
fimpara

Answer 2

The para .. faca (do) is a repeating structure of the portugol with control variables, and serves for you to run a certain internal code block by n times.

A simple example:

algoritmo "contador"
    var
    C: inteiro
inicio
      Para C <- 1 ate 10 faca
      Escreva (C)
      Fimpara
fimalgoritmo

The output of this algorithm in Visualg will be:

1 2 3 4 5 6 7 8 9 10

* End of execution. * Close this window to return to Visualg.

In addition to using Visualg in your studies, I also advise you to watch this class, and consult this manual.

Good studies.

Answer 3

In other words the function will do the same task a certain number of times

Example in a race:

It will start with around 0 /int x = 0; (in Lucas Henrique’s model)

It will have 100 laps // x <= 100; (in Lucas Henrique’s model)

For each completed lap add +1 // x++; (in Lucas Henrique’s model)

Below this statement you inform what the program will do, in case the race would run the run function until complete the 100 laps.

I hope I’ve helped

Answer 4

for(int x = 0; x <= 10; x++) { //code to be incremented }

whereas int x = 0 => is creating an integer variable x that gets 0, which is the starting point of your repeat loop. That is, it will start at 0.

x<= 10 => it will perform until the condition is less than or equal to 10.

x++ => is the incrementing of your loop. In this case, it represents that it will add the initial value to each iteration.

Answer 5

The for is usually used to make iterations (defined by the language or by a language resource) or also as a conditional loop defined as follows:

1. Value of the scope variable to be created
2. Condition of existence of the loop
3. Unconditional function of the loop

Regarding the two possibilities, I take Python and C. Iterators:

for x in range(0,100):
    # faça o que quiser aqui com "x"

And on condition:

for(int x = 0; x <= 100; x++)