01 · Overview

About Calango

Calango is a pseudolanguage and learning environment for algorithms. Its Portuguese commands keep attention on steps, conditions, and data before learners move on to the syntax of other languages. Materials from the University of Brasília describe its educational use, interpreted execution, and step-by-step debugging.

This reference combines that teaching purpose with the Calango structures described in the sources at the end of the page.

02 · Organization

Algorithm structure

The header starts with algoritmo, followed by a name and semicolon. The main block starts with principal and ends with fimPrincipal. Functions and procedures appear outside this block.

algoritmo boasVindas;
principal
    texto nome;
    escreva("What is your name?");
    leia(nome);
    escreval("Hello, ", nome);
fimPrincipal

A line beginning with // is a comment. The body can contain declarations and commands; simple statements end with semicolons.

03 · Data

Types, variables, and vectors

Declare a variable by writing its type followed by its name. Basic types include inteiro, real, logico, caracter, and texto. Text literals use double quotes; real numbers use a decimal point; logical values are verdadeiro and falso.

inteiro quantidade;
real preco;
logico disponivel;
caracter inicial;
texto titulo;
inteiro notas[5];

quantidade = 3;
preco = 2.5;
disponivel = verdadeiro;
titulo = "Algorithms";
notas[0] = 10;

Vectors are declared by adding dimensions in square brackets after the name. Access an element with brackets as well. The interpreter accepts multiple dimensions; every index must be an integer.

04 · Expressions

Assignment and operators

Assignments use =. Parentheses group operations. The table summarizes arithmetic forms, comparisons, and logical connectors in the documented syntax.

Category	Operators	Use
Arithmetic	`+ - * / \ % mod`	Calculations, division, and remainder.
Comparison	`= == != <> < <= > >=`	Compare values.
Logical	`nao e ou`	Negate or combine conditions with AND/OR.

real total;
total = preco * quantidade;
se (quantidade > 0 e disponivel) entao
    escreva("Total: ", total);
fimSe

Use mod or % to get a remainder. Precedence follows mathematical and logical priorities; parentheses make long expressions easier to read.

05 · Interaction

Input and output

escreva(...) displays values; escreval(...) adds a line break. Both accept comma-separated expressions. leia(...) reads a value for a variable, and leiaCaracter(...) is the dedicated character input form.

texto nome;
inteiro idade;
escreva("Name: ");
leia(nome);
escreva("Age: ");
leia(idade);
escreval("Hello, ", nome, " — ", idade, " years old.");

limpaTela(); clears the output area. Input should match the declared type of its destination variable.

06 · Decisions

Conditions and choice

se begins a conditional block; senaoSe tests another condition and senao defines the final branch. The block ends with fimSe. escolha compares an expression with caso alternatives and can include outroCaso.

se (nota >= 7) entao
    escreval("Passed");
senaoSe (nota >= 5) entao
    escreval("Review period");
senao
    escreval("Not passed");
fimSe

escolha opcao
    caso 1
        escreval("New exercise");
    outroCaso
        escreval("Unknown option");
fimEscolha

Conditions must produce a logical value. Each caso runs the block associated with its matching value.

07 · Repetition

Enquanto, faça-enquanto, and para

enquanto checks its condition before the body. faca ... enquanto runs first and checks at the end. para traverses a numeric sequence with explicit start, end, and step values.

inteiro i;
i = 1;
enquanto (i <= 3) faca
    escreval(i);
    i = i + 1;
fimEnquanto

para i de 1 ate 3 passo 1 faca
    escreval(i);
fimPara

interrompa; immediately exits the innermost loop. Avoid conditions that never become false.

08 · Reuse

Functions, procedures, and parameters

A function declares its return type before its name and ends with fimFuncao. A procedure has no return type and ends with fimProcedimento. Parameters appear in parentheses with type and name; ref marks a reference parameter. retorna returns a function result.

funcao inteiro dobro(inteiro valor)
    retorna valor * 2;
fimFuncao

procedimento mostrar(texto mensagem)
    escreval(mensagem);
fimProcedimento

principal
    escreval(dobro(4));
    mostrar("Practice one step at a time");
fimPrincipal

Call a routine by name with the arguments it expects. Use reference parameters when a routine should update the variable it receives.

09 · In practice

Complete example

This program reads three grades, calculates the average, and reports a result using a vector, loop, and condition.

algoritmo mediaTurma;
principal
    inteiro i;
    real notas[3];
    real soma;
    soma = 0;
    para i de 0 ate 2 passo 1 faca
        escreva("Grade: ");
        leia(notas[i]);
        soma = soma + notas[i];
    fimPara
    se (soma / 3 >= 7) entao
        escreval("Passed");
    senao
        escreval("Keep studying");
    fimSe
fimPrincipal

10 · Sources

References

Official Calango repository.
Algorithm environment — University of Brasília, on interpretation, execution, and educational use.

Examples on this page were written to explain the syntax and do not reproduce long passages from the reference materials.

Calango