what is the uri in mongoose code example

Example 1: mongoose connection node

mongoose.connect('mongodb://localhost/myapp', { useNewUrlParser: true, useUnifiedTopology: true });

Example 2: TypeError: mongoose__WEBPACK_IMPORTED_MODULE_2___default.a.connect is not a function at _callee$ (db.js:11) at tryCatch (runtime.js:45)

try {
  mongoose.connect(MONGODB_URI || 'mongodb://localhost/YOUR_DB_NAME', {
      useNewUrlParser: true,
      useUnifiedTopology: true
    }, () =>
    console.log("connected"));
} catch (error) {
  console.log("could not connect");
}