I want to get the value of an inline function.

let WIDTH;
Image.getSize(imageUri, (width, height) => {
    const ratio = height / width;
    WIDTH = HEIGHT / ratio;
});
  
console.log(WIDTH);

The code prints undefined.

I tested this aswell:

let WIDTH = Image.getSize(imageUri, (width, height) => {
    const ratio = height / width;
    return HEIGHT / ratio;
  });

  console.log(WIDTH);

And got the same undefined result.