how to creat user in mongo database code example

Example 1: create admin user in mongodb

use admin
db.createUser(
      {
          user: "username",
          pwd: "password",
          roles: [ "root" ]
      }
  )

Example 2: mongodb create user

use admin
db.createUser(
   {
     user: "restricted",
     pwd: passwordPrompt(),      // Or  "<cleartext password>"
     roles: [ { role: "readWrite", db: "reporting" } ],
     authenticationRestrictions: [ {
        clientSource: ["192.0.2.0"],
        serverAddress: ["198.51.100.0"]
     } ]
   }
)