如何將數據存儲在箭頭 function 中？

Question

這是我let s箭頭 function 中，我將其存儲在一個循環中，並將所有 object 合並到object.assign中。 但是，當我運行let s arrow function 時，出現 Promise { undefined } 錯誤。

let s = async() => {
  Object.values(sqlQuery).map(async(o:any) => {
    a.map(async(k:any) => {
      c.map(async(l:any) => {
        var district:any = `select slug from foa_section_content where foa_section_content_id IN (${k})`;
        var [district1]: any = await connection.execute(district);
        var commune:any = `select slug from foa_section_content where foa_section_content_id IN (${l})`;
        var [commune1]: any = await connection.execute(commune);

        s = await (Object.assign(o,{district1},{commune1}))
   
                  })
    })
    
  })
}
    return (s());

Answer 1

問題是您沒有從箭頭 function 返回值。箭頭 function 的語法是：

    let s = async() => {
  return Object.values(sqlQuery).map(async(o:any) => {
    a.map(async(k:any) => {
      c.map(async(l:any) => {
        var district:any = `select slug from foa_section_content where foa_section_content_id IN (${k})`;
        var [district1]: any = await connection.execute(district);
        var commune:any = `select slug from foa_section_content where foa_section_content_id IN (${l})`;
        var [commune1]: any = await connection.execute(commune);

        return Object.assign(o,{district1},{commune1});
   
                  })
    })
    
  });
}