在 TypeScript 中 unknown 与 any 相比，unknown 比 any 类型更安全。例子如下

    1. function func1(value: any) {
    2.     value.toFixed(2)
    3.   value[11] = 1
    4.   value.split(',')
    6.  // no error
    7. }
    9. function func2(value: unknown) {
    10.     value.toFixed(2)  // (parameter) value: unknown Object is of type 'unknown'.
    11.   value[11] = 1  // (parameter) value: unknown Object is of type 'unknown'.
    12.   value.split(',')  // (parameter) value: unknown Object is of type 'unknown'.
    14.   (value as number).toFixed(2)
    15.   (value as object)[11] = 1
    16.   (value as string).split(',')
    17. }

    image.png

    https://2ality.com/2020/06/any-unknown-typescript.html https://stackoverflow.com/a/51439876