What is and how to use destructuring

Destructuring is a feature of several programming languages that allows decomposing complex data structures (such as tuples, collections, and objects), and assigning them to individual variables.

In summary, many languages allow composing variables into collections or groupings. It is common that at some point we want to “undo” this composition and create individual variables for each of the members.

Destructuring allows us to perform this operation concisely. Let’s see it with an example. Suppose we have a grouping person, which contains name and age.

// composition
const person = { name: "Luis", age: 30 };

// traditional decomposition
const name = person.name;
const age = person.age;

// with destructuring
const { name, age } = person;

Destructuring person allows us to create two new variables name and age, in a simpler way than with “traditional” variable assignment.

Example of destructuring in different languages

Not all languages that incorporate destructuring allow destructuring all types. However, it is a trend that they increasingly expand this functionality because it is sometimes very convenient.

Let’s see how different languages incorporate the concept of destructuring to a greater or lesser extent.

var tuple = (1, "Hello", 3.5);

var (integer, greeting, number) = tuple;

struct Person {
    std::string name;
    int age;
};

Person person = {"John", 30};
auto [name, age] = person;

const person = { name: "Luis", age: 30 };
const { name, age } = person;

const numbers = [1, 2, 3];
const [first, second, third] = numbers;

tuple = (1, "Hello", 3.5)
number, greeting, decimal = tuple