Javascript（node.js）数组转换为特定的字符串格式（类似于JSON）

Question

All my digging and searching online did not result to find me right method to get the following string in required format, I can of course concatenate and achieve this in crude way, however I'm eager to learn Javascript + JSON. I'm using the string in node.js express basic authentication.

I need to build the following string (the one only inside the curly braces):

app.use(basicAuth(...
  users: { 'admin': 'adminpass' , 'user':'userpass'},.....

Code to fetch the data from database:

connection.query('SELECT * FROM wts_users', function (error, results, fields) {
  if (error) throw error;
  for (var i = 0; i < results.length; i++) {
    var result = results[i];
    userList.push(result.user_name, result.user_password)
  }
  console.log("user list: "+JSON.stringify(userList));
});

The result I'm getting:

["admin","adminpass","user","userpass"]

How can I get the result in the below format.

{ 'admin': 'adminpass' , 'user':'userpass'}

Answer 1

userList should be an object

userList = {};
userList[result.user_name] = result.user_password;

Alternatively, you can use Array.reduce

 let results = [{user_name: "admin", user_password : "adminpass"}, {user_name: "user", user_password : "userpass"}] let userList = results.reduce((o, {user_name, user_password}) => Object.assign(o, {[user_name] : user_password}), {}); console.log("user list: "+JSON.stringify(userList)); 

Answer 2

This is the appropriate time to use reduce :

const userList = results.reduce((a, { user_name, user_password }) => {
  a[user_name] = user_password;
  return a;
}, {});

Answer 3

Using userList as an object is the correct way. But if you already have an array and must necessarily convert it into an object, taking elements 2 by 2, you may use this function:

function toObject(arr) {
  var obj = {};
  for (var i = 0; i < arr.length; i+=2)
    obj[arr[i]] = arr[i+1];
  return obj;
}

Demo

 let result = ["admin","adminpass","user","userpass"] function toObject(arr) { var obj = {}; for (var i = 0; i < arr.length; i+=2) obj[arr[i]] = arr[i+1]; return obj; } console.log(toObject(result));