Array of object - get id for selected user name inside function-CodePudding

const user = [
{name:"jonh" ,id:EAD1234},
{name:"peter" ,id:EAD1235},
{name:"matt" ,id:EAD1236},
{name:"henry" ,id:EAD1237},
]

I have above mentioned array of object, I want to get selected user id dynamically based on user selection using es6 and javascript e.g. if i select john i should get EAD1234. and it must suitable on large number of records

I tried using filter method

CodePudding user response：

If the data is samll,then just combine Array.filter() and Array.map() can do it.

If the data is too large,we can store the data into a database such as mysql or redis,then query it dynamiclly

const user = [
{name:"jonh" ,id:'EAD1234'},
{name:"peter" ,id:'EAD1235'},
{name:"matt" ,id:'EAD1236'},
{name:"henry" ,id:'EAD1237'}
]

let id = 'EAD1234'
let result = user.filter(u => u.id === id).map(u => u.name)
console.log(result)

CodePudding user response：

No need to filter through the whole array if the id values are unique:

function getUserByID(id, users) {
  for (const u of users) {
    if (u.id === id) {
      return u;
    }
  }
  return null;
}

If your data really is exceptionally large and it makes sense to store it on the front-end look into using IndexedDB.

Edit: Someone in the comments somewhere mentioned Array.prototype.find(), so you might as well just use the built-in.

function getUserByID(id, users) {
  return users.find((u) => u.id === id) || null;
}

CodePudding user response：

const user = [
    {name:"john"  ,id:'EAD1234'},
    {name:"peter" ,id:'EAD1235'},
    {name:"matt"  ,id:'EAD1236'},
    {name:"henry" ,id:'EAD1237'},
];

let userName = "john";
let userId = user.filter(user => user.name === userName)[0].name;