// basic sample var numbers = [1, 4, 9]; var roots = numbers.map(Math.sqrt); // sample with objects var users = [ {name:'john', email:'jrw@mit.edu'}, {name:'bruce', email:'bruce@mit.edu'}, {name:'abel', email:'abel@mit.edu'} ]; var namePlusEmail = users.map(function(user){ return user.name + ' <' + user.email + '>'; }); // roots=[1, 2, 3] // namePlusEmail=["john
", // "bruce
", "abel
"]