CODE EXAMPLE FOR JAVASCRIPT

regex in mongo query

var search ='Neha';

db.members.find(name: new RegExp(search)) //For substring search, case sensitive. 

db.members.find(name: new RegExp('^' + search + '$')) //For exact search, case sensitive

db.members.find(name: new RegExp(search， ‘i')) //For substring search, case insensitive

db.members.find(name: new RegExp('^' +search + '$', 'i')); //For exact search, case insensitive