如何将字符串追加到数组列表中的每个项目

Question

项目应显示，并在附加国家/地区代码后以逗号分隔，例如44904223322,44504905949,44304940393

const students = [{
    name: "Anna",
    sex: "f",
    grades: [4.5, 3.5, 4]
  },
  {
    name: "Dennis",
    sex: "m",
    country: "Germany",
    grades: [5, 1.5, 4]
  },
  {
    name: "Martha",
    sex: "f",
    grades: [5, 4, 2.5, 3]
  },
  {
    name: "Brock",
    sex: "m",
    grades: [4, 3, 2]
  }
];

const sum = (a, b) => a + b;
const femaleStudentsResults = students
  .filter(({ sex }) => sex === 'f')
  .map(({ name, grades }) => ({ name, avgGrade: grades.reduce(sum) / grades.length }));
console.log(femaleStudentsResults);

Answer 1

您可以缩短代码，并在添加到音标时（在此更改为phoneList）添加“ 44”。

 List<string> phoneList = new List<string>();
 conn.Open();
 MySqlCommand sda = new MySqlCommand("select * from members where Branch='" + lbladminbranch.Text + "' and Country='" + lbladmincountry.Text + "'", conn);

 MySqlDataReader dr = sda.ExecuteReader();

 while (dr.Read())
 {
    phoneList.Add("44" + dr["Phone"].ToString());
 }
 txtsmsphoneno.Text = string.Join(",",phoneList);
 conn.Close();