如何在TypeScript中将箭头函数返回值分配给string []

Question

I have the following cast issue with the typescript code below:

Error:

Type '() => string[]' is missing the following properties from type 'string[]': pop, push, concat, join, and 24 more. function stringArray(): string[]

function stringArray(): string[] {

    return ['a', 'b', 'c']
}

let a: string[]

a = (): string[] => stringArray() 

I simplified the code so nobody has to understand the actual problem I'm trying to solve. The main question is how can I define the return value of the arrow function to be accepted for the assignment of a .

Answer 1

This is happening because you are assigning an arrow function reference in the variable a .

function stringArray(): string[] {

    return ['a', 'b', 'c'];
}

let a: Function;

a = (): string[] => stringArray();

Instead you should set the type as Function

Or you can invoke the arrow function to return the array ['a', 'b', 'c'] :

function stringArray(): string[] {

    return ['a', 'b', 'c'];
}

let a: string[];

a = ((): string[] => stringArray())();

To make it simple:

 function stringArray(): string[] {

    return ['a', 'b', 'c'];
 }

 let a: string[];

 a = stringArray();

Answer 2

You are assigning another arrow function to a. To assign the return value to a, invoke the function in assignment.

let a: string[]
a = stringArray()