strict vs loose equality with undefined and null

// see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Equality_comparisons_and_sameness [ // loose equality with || 'undefined != undefined || undefined != null', 'null != undefined || null != null', '123 != undefined || 123 != null', '"foobar" != undefined || "foobar" != null', // loose equality with && 'undefined != undefined && undefined != null', 'null != undefined && null != null', '123 != undefined && 123 != null', '"foobar" != undefined && "foobar" != null', // strict equality with || 'undefined !== undefined || undefined !== null', 'null !== undefined || null !== null', '123 !== undefined || 123 !== null', '"foobar" !== undefined || "foobar" !== null', // strict equality with && 'undefined !== undefined && undefined !== null', 'null !== undefined && null !== null', '123 !== undefined && 123 !== null', '"foobar" !== undefined && "foobar" !== null', ].forEach((booleanLogic) => console.log(`${eval(booleanLogic)} === (${booleanLogic})`));