Don't use == and !=, use === and !==. Then, watch this video to learn why.
Cool article about Brendan Eich creating JS: https://thenewstack.io/brendan-eich-o...
The official JavaScript spec, that defines what JavaScript (technically ECMAScript) is: https://www.ecma-international.org/pu...
The specific part in the spec that talks about how == and === work: https://www.ecma-international.org/ec...
The spec calls what == does "abstract equality comparison" and what === "strict equality comparison"