your exists syntax is wrong and you should seperate DDL with go like below
if exists(select 1 from sys.views where name="tst" and type="v")
drop view tst;
go
create view tst
as
select * from test
you also can check existence test, with object_id like below
if object_id('tst','v') is not null
drop view tst;
go
create view tst
as
select * from test
In SQL 2016,you can use below syntax to drop
Drop view if exists dbo.tst
From SQL2016 CU1,you can do below
create or alter view vwTest
as
select 1 as col;
go