How to cast to array in TypeScript 2?
For some reason the compiler thinks that result.data['value']
is a tuple and not an array.
You can cast it like this:
result.data['value'] as any[]
Which should tell the compiler that it's an array, or:
result.data['value'] as Array<any>
If your array has only items of type IMyType
then simply:
result.data['value'] as IMyType[]
However, if your array contains items of different types then it's either a any[]
or a tuple, for example:
result.data['value'] as [IMyType, string, string]
In any case, in the compiled js it will be an array, but tuples let you define a fixed length arrays with specific types.
You're not casting to an array.
[string]
is a tuple with a single element string
.
[string, string]
is a tuple with two elements, string
and string
.
[]
is a tuple with zero elements.
The syntax for an array of strings is string[]
What you likely want is result.data['value'] as any[]
.
Alternatively to the previous cast syntax options mentioned above, you can also do the following:
var n = (<SampleType[]>result.data['value']).map((a) => { //..});