Why FormData object is empty even after I use append?

Question

I tried the following code: (This is my service file in angular posts.service.ts)

 updatePost(id: string, title: string, content: string, image: File | string) {
        let postData: Post | FormData;
        console.log(id);
        if(typeof(image) === 'object'){
            console.log("Image is object");
            const postData = new FormData();
            postData.append('id',id);
            postData.append('title',title);
            postData.append('content', content);
            postData.append('image', image, title);
            console.log(postData)
        } else {
            console.log("In else!")
            postData = { id: id, title: title, content: content, imagePath: image };
        }

When I check console.log(postData), it is empty.