Is there a substr method in jade template?

Is there exist some string method in jade template?

Like subStr, slice, toLowerCase?

I can find this API in it's doc

Where I can find them?

You can work with variables in template as is. So it's just JavaScript variables.

html
    head
        title= title.toUpperCase()
    body
        p= text.substr(1, 100) + '...'