In the function getName I loop through the static properties of the class UnitGroups. The function should return the property's identifier fitting to the passed value. E.g. UnitGroups.getName(1) should return "Speed".
export default class UnitGroups {
static Length = 0;
static Speed = 1;
static Area = 2;
static Mass = 3;
static Volume = 4;
static VolumeFlowRate = 5;
static Temperature = 6;
static Time = 7;
static Acceleration = 8;
static Charge = 9;
static Force = 10;
static Voltage = 11;
static Power = 12;
static Energy = 13;
static Pace = 14;
static Pressure = 15;
static Illuminance = 16;
static PartsPer = 17;
static Current = 18;
static ApparentPower = 19;
static ReactivePower = 20;
static ReactiveEnergy = 21;
static Angle = 22;
static Digital = 23;
static Frequency = 24;
public static getName(unitGroup: number) {
for (const property in UnitGroups) {
const number = UnitGroups[property];
if (number === unitGroup) return property;
}
}
}
My code works completely fine but typescript throws following error (appears when hovering over UnitGroups[property]):
Element implicitly has an 'any' type because expression of type 'string' can't be used to index type 'typeof UnitGroups'.
No index signature with a parameter of type 'string' was found on type 'typeof UnitGroups'.ts(7053)
I don't understand the error and the error message...
Looks like TypeScript does not infer type in the for..in loop correctly.
You can add a hint for the compiler as follows:
const number = UnitGroups[property as keyof UnitGroups];
Alternatively, for your particular case you can use an enum to implement the same behaviour:
enum UnitGroupType {
Length = 0,
Speed = 1,
Area = 2,
// ...
}
function getName(type: UnitGroupType) {
return UnitGroupType[type]
}