what is the correct way to use toolbar?

[funbinod]

i'm trying to set actionbar on my android studio project. while debugging, android studio doesn't show any error but when i run my app, it stops at this line. please suggest me the perfect way of working with toolbar on android studio.

Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);

thank you all in advance.