example.js

var datas;
db.transaction(function(transaction){
    transaction.executeSql('SELECT * FROM Comics WHERE name = ? ',
        [["batman"]],
        function(transaction,result){
            for(var i = 0; i < result.rows.length;i++){
                datas = result.rows.item(i)['name'];

            }
        },
        function(transaction,error){
            console.log(error);
        })
    });
console.log(datas); // outputs undefined