# E0344: using '===' or '!==' against an empty array literal always produces the same result

Using the strict equality operator against an empty array literal will always return 'false', and using the strict inequality operator will always return 'true'. e.g. the conditions below will always be 'false' and 'true' respectively, no matter what value 'x' holds.

    let x = [];

    // the expression inside the if statement is always 'false'
    if (x === []) {
    }

    // the expression inside the if statement is always 'true'
    if (x !== []) {
    }

To fix this particular example, we could compare the length of the array

    let x = [];

    if (x.length === 0) {
    }

Introduced in quick-lint-js version 2.10.0.

Documentation for other errors