mongoose not connecting to mongodb code example

Example 1: mongoose connection node

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

Example 2: node js connect to mongodb using mongoose

//connect with mongodb
mongoose.connect('mongodb://localhost:27017/your_db_name', {useNewUrlParser: true});
//you can also specify with user and pass
mongoose.connect('mongodb://username:password@host:port/database?options...', {useNewUrlParser: true});
//or goto docs https://mongoosejs.com/docs/connections.html