Struct in Ionic Framework [duplicate] - swift

Question

I have a struct like so:
struct tTest{
char foo [1+1];
char bar [64];
};
In TypesScript I have
export interface tTest{
foo: string;
bar: string;
}
Is there a way to add [64] and [1+1] to the type?

Answer 1

As the comments say: js/ts don't support the char type and there's no way to declare array/string lengths.
You can enforce that using a setter though:
interface tTest {
foo: string;
}
class tTestImplementation implements tTest {
private _foo: string;
get foo(): string {
return this._foo;
}
set foo(value: string) {
this._foo = value;
while (this._foo.length < 64) {
this._foo += " ";
}
}
}
(code in playground)
You'll need to have an actual class as the interfaces lacks implementation and doesn't survive the compilation process.
I just added spaces to get to the exact length, but you can change that to fit your needs.

Answer 2

You can't force the length of an array in Typescript, as you can't in javascript.
Let's say we have a class tTest as following:
class tTest{
foo = new Array<string>(2);
};
As you can see, we have defined an array of string with length 2, with this syntax we can restrict the type of values we can put inside our array:
let t = new tTest();
console.log('lenght before initialization' + t.foo.length);
for(var i = 0; i < t.foo.length; i++){
console.log(t.foo[i]);
}
t.foo[0] = 'p';
t.foo[1] = 'q';
//t.foo[2] = 3; // you can't do this
t.foo[2] = '3'; // but you can do this
console.log('length after initialization' + t.foo.length);
for(var i = 0; i < t.foo.length; i++){
console.log(t.foo[i]);
}
In this manner we can't put a number value inside your array, but we can't limit the number of values you can put inside.
Playground