Avoid comparisons where both sides are exactly the same

Documentos > Code Analysis > Static Analysis Rules > Avoid comparisons where both sides are exactly the same

This page is not yet available in Spanish. We are working on its translation.
If you have any questions or feedback about our current translation project, feel free to reach out to us!

Metadata

ID: javascript-code-style/no-self-compare

Language: JavaScript

Severity: Warning

Category: Error Prone

Description

Comparing a variable to itself is most likely a mistake.

Non-Compliant Code Examples

if (x === x) { }
if (x !== x) { }
if (x > x) { }
if ('x' > 'x') { }
do {} while (x === x)
x === x
x !== x
x == x
x != x
x > x
x < x
x >= x
x <= x
foo.bar().baz.qux >= foo.bar().baz.qux
class C { #field; foo() { this.#field === this.#field; } }

Compliant Code Examples

if (x === y) { }
if (1 === 2) { }
y=x*x
foo.bar.baz === foo.bar.qux
class C { #field; foo() { this.#field === this['#field']; } }
class C { #field; foo() { this['#field'] === this.#field; } }