I am getting error in this implementation of typescript code. I am mapping here one type to another. But vscode shows error that variable 'test' is used before being assigned. can anyone please help?
interface A {
name: string;
age: string;
sex: string;
}
interface B {
name: any;
age: string;
sex: string;
}
const modifyData = (g : B) :A => {
let test: A;
test.name = g.name['ru'];
test.age = g.age;
test.sex = g.sex;
return test as A;
};
const g = [{
"name": {
"en": "George",
"ru": "Gregor"
},
"age": "21",
"sex": "Male"
},
{
"name": {
"en": "David",
"ru": "Diva"
},,
"age": "31",
"sex": "Male"
}];
const data = g.map(modifyData);
console.log(data);
It is indeed unassigned. It is defined, but it has no value.
To give an example
let text: string; // variable `text` gets defined, but it has no assigned value - it is defined but unassigned
if (Math.random() > 0.5) {
text = "heads";
}
// console.log(`We flipped ${text}`) // this would be an error for the compiler as the variable text might still not have a value assigned to it
text = "tomato"; // here we finally guarantee that text will have a value assigned to it and we can safely use it as string
console.log(`We found ${text}`)
In my humble opinion, the cleanest way would be to return a literal:
const modifyData = (g: B):A => {
return {
name: g.name['ru'],
age: g.age,
sex: g.sex
} as A;
};