typescript 如何给Class中所有参数加上可选？-灵析社区

class A { a: number = 0; b: string = 'aa'; } class B extends ({} as new () => Partial) { c: string = "2312" } 参考：[StackOverflow - Typescript class extending Partial interface](https://link.segmentfault.com/?enc=Dn05fkdGg9T10LRiZaCnkg%3D%3D.o0DgvOPaCCXO36L5Mg%2FozGU2K%2F3wE9V4Z4YT80xkcNuBaMKAm2PiF48Y2RucRhrDERnZvStPjAC%2FXstTmjg8G6oRLeWbXoM3aCoQQbv6ZpN%2BXWglnZOSQJuB6EE09NRm)