Recently, I came across this interesting function:
function fn(param: Record<string, unknown>) {
//...
}
x({ hello: "world" }); // Everything runs smoothly
x(["hi"]); // Error -> Index signature for type 'string' is missing in type 'string[]'
It is logical because the Index Signature in an Array is typically a Number, whereas in a Record it is defined as a string.
However,
If I replace unknown with any, like so:
function fn(param: Record<string, any>) {
//...
}
x({ hello: "world" }); // No issues
x(["hi"]); // Works perfectly fine now
The Question Arises: Even though only the Value has been changed to Any and not the Key type in Record, why am I not encountering any errors despite the Index Signature for arrays being Number and for records being string?