Question

Hi everyone I’m having difficulty understanding the following function structures.

Could somebody walk me through it please? I’m doing it as part of my JS course.

I have tested the functions and have seen the output but I’m not sure how JS comes to that conclusion.

Thanks in advance.

// Number 1

function doit(m){
    return(m+2);
}
function ask(n){
    return(n+doit(n+1)+n);
}
alert(ask(2));

// Number 2

function doit(n){
    return(n+1);
}
function ask(p,q){
    return(p+doit(q+2)+q);
}
alert(ask(2,3));

I am not sure how to read it!

Answer 1

function doit(m){
    return(m+2);
}
function ask(n){
    return(n+doit(n+1)+n);
}
ask(2);

ask is a function that takes one parameter and does the following

• add n to it. +n at the end.
• adds the return value of doIt(n+1) to it.

Thus we have n + n + doIt(n+1)

Now doIt is another function that takes a value and returns it’s but incremented twice.

This gives us a total of n + n + n + 1 + 2 Which is 3*(n+1)

Example two is left as an exercise for the reader