An Alternative Approach to Implementing the Ternary Operator in JavaScript

Question

An Alternative Approach to Implementing the Ternary Operator in JavaScript

Do you find this logical operation to be rational?

const user = users && users[0] || null;

Is it identical to this conditional or ternary operation:

const user = users ? users[0] : null;

? Let's assume users represents an array.

javascript arrays conditional-operator

Answer 1

Answer №1

They are not identical. If users[0] evaluates to false, the first code will select || null:

const users = [0];
const user1 = users && users[0] || null;
const user2 = users ? users[0] : null;

console.log(user1, user2);

The ternary operator may be a better option. Alternatively, you can use optional chaining in modern JavaScript for more succinct code:

let users;

const user = users?.[0];
console.log(user);

(However, note that it returns undefined if the nested property does not exist, not null)

Answer 2

They are not identical. If users[0] evaluates to false, the first code will select || null:

const users = [0];
const user1 = users && users[0] || null;
const user2 = users ? users[0] : null;

console.log(user1, user2);

The ternary operator may be a better option. Alternatively, you can use optional chaining in modern JavaScript for more succinct code:

let users;

const user = users?.[0];
console.log(user);

(However, note that it returns undefined if the nested property does not exist, not null)

Answer 3

Answer №2

Simply using the users variable by itself may not be the most effective method for conducting tests. In certain programming languages such as Go, testing against boolean values is a common practice. Therefore, it would be more efficient to conduct tests against a boolean value whenever possible. Consider utilizing a structure similar to the following:

const user = users.length > 0 ? users[0] : null;

Answer 4

Simply using the users variable by itself may not be the most effective method for conducting tests. In certain programming languages such as Go, testing against boolean values is a common practice. Therefore, it would be more efficient to conduct tests against a boolean value whenever possible. Consider utilizing a structure similar to the following:

const user = users.length > 0 ? users[0] : null;

An Alternative Approach to Implementing the Ternary Operator in JavaScript

Answer №1

Answer №2

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