Decompressing an array within a function invocation

Question

Decompressing an array within a function invocation

Is there a method to pass an array's elements as arguments to a function?

For instance, in Python I can accomplish this using:

user = ["John", "Doe"]

def full_name(first_name, last_name):
    return first_name + last_name

Therefore, full_name(*user) unpacks the user array and uses each item as an argument for the full_name function.

Can a similar functionality be achieved in JavaScript/TypeScript?

javascript typescript

Answer 1

Answer №1

You should utilize the ...spread operator.

const user = ["John", "Doe"] as const

function fullName(firstName: string, lastName: string): string {
    return firstName + lastName
}

fullName(...user)

Take note of the as const.

To ensure type safety in Typescript, the array must be a two-item tuple of type [string, string], rather than just an array with unknown length like string[]. This is necessary to guarantee type safety as there must be at least 2 strings in the array to fulfill both arguments. Using as const instructs Typescript to treat the array as a tuple with known strings and fixed length.

Interactive Example

Answer 2

You should utilize the ...spread operator.

const user = ["John", "Doe"] as const

function fullName(firstName: string, lastName: string): string {
    return firstName + lastName
}

fullName(...user)

Take note of the as const.

To ensure type safety in Typescript, the array must be a two-item tuple of type [string, string], rather than just an array with unknown length like string[]. This is necessary to guarantee type safety as there must be at least 2 strings in the array to fulfill both arguments. Using as const instructs Typescript to treat the array as a tuple with known strings and fixed length.

Interactive Example

Answer 3

Answer №2

One way to handle the parameter in the full_name function is by using array destructuring:

const person = ["Jane", "Smith"];

const full_name = ([first, last]) =>
    first + last;

full_name(person);

Another option is to utilize the spread operator (...) when invoking the full_name function with an array as the parameter:

const person = ["Jane", "Smith"];

const full_name = (first, last) =>
    first + last;

full_name(...person);

Answer 4

One way to handle the parameter in the full_name function is by using array destructuring:

const person = ["Jane", "Smith"];

const full_name = ([first, last]) =>
    first + last;

full_name(person);

Another option is to utilize the spread operator (...) when invoking the full_name function with an array as the parameter:

const person = ["Jane", "Smith"];

const full_name = (first, last) =>
    first + last;

full_name(...person);

Answer 5

Answer №3

You can accomplish this by utilizing the spread operator in JavaScript.

const person = ["Mary", "Smith"]

function printFullName(first, last) {
    return first + ' ' + last;
}

printFullName(...person);

Answer 6

You can accomplish this by utilizing the spread operator in JavaScript.

const person = ["Mary", "Smith"]

function printFullName(first, last) {
    return first + ' ' + last;
}

printFullName(...person);

Answer 7

Answer №4

Consider utilizing Destructuring assignment. Here's an example:

const complete_name = (arr) => {
    const [first, last] = arr;
    return `${first} ${last}`;
};

var person = ["Jane", "Smith"];
console.log(complete_name(person)); // output: Jane Smith

Answer 8

Consider utilizing Destructuring assignment. Here's an example:

const complete_name = (arr) => {
    const [first, last] = arr;
    return `${first} ${last}`;
};

var person = ["Jane", "Smith"];
console.log(complete_name(person)); // output: Jane Smith

Decompressing an array within a function invocation

Answer №1

Answer №2

Answer №3

Answer №4

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