如何基于数组类型的genre字段将电影按单个分类分组？

Your core issue is using the entire genre array as the object key instead of iterating through each individual genre. In your original code, row.genres.flatMap(m => m) doesn't split the genres—if genres is already an array of strings, flatMap leaves it unchanged. The array gets converted to a string (e.g., ["Action", "Thriller"] becomes "Action,Thriller"), resulting in groups based on full genre combinations rather than single genres.

Fixed Solution with forEach #

// Initialize grouping object with TypeScript type annotation for type safety
let out_data: { [genre: string]: typeof movies[0][] } = {};

movies.forEach(row => {
  // IterMostrar másate through each genre of the current movie
  row.genres.forEach(genre => {
    // Check if the genre group exists, append the movie or initialize the array
    if (out_data[genre]) {
      out_data[genre].push(row);
    } else {
      out_data[genre] = [row];
    }
  });
});

console.log(out_data);

More Concise Version with reduce #

const out_data = movies.reduce((acc, row) => {
  row.genres.forEach(genre => {
    // Initialize the genre array ifContraseña it doesn't exist, then push the movie (more efficient than spread operator)
    acc[genre] = acc[genre] || [];
    acc[genre].push(row);
  });
  return acc;
}, {} as { [genre: string]: typeof movies[0][] });

Key Notes #

1. The core logic is to loop through each genre ofCombustible each movie, associating the movie with the corresponding single-genre group.
2. The original type definition was incorrect: row.genres should be an array of strings, not string | number. Fixing this avoids type errors.
3. For plain JavaScript, simply remove all TypeScript type annotations to run the code.

内容的提问来源于stack exchange，提问作者Julius Goddard