predifned functions in javascript

In javascript there are lots of predifine function which can be called to give answers:

1) . length function

2) .include function

3) math function

4) trim()

5) replace()

6) index of()

7) chartAt()

8) slice()

How to get input from user:

let name = prompt('enter your name ')

Note: the input data in prompt is by default a string

To change the default types of input data to number we use: parseint before prompt()