Do chapter 5 Problems

Here they are:

    1. Dynamic type binding is closely related to implicit heap-dynamic variables. Explain this relationship.

    2. Consider the following JavaScript skeletal program:

    • The main program var x;

function sub1() { var x; function sub2() {
. . .
}
}
function  sub3() {
. . .
}

Assume that the execution of this program is in the following unit order:

main calls sub1

sub1 calls sub2

sub2 calls sub3

a. Assuming static scoping, in the following, which declaration of x is the correct one for a reference to x?

                i. sub1

            ii. sub2

                iii. sub3

        b. Repeat part a, but assume dynamic scoping.

    3. Consider the following JavaScript program:


var    x, y, z;

function    sub1() {
var    a, y, z;
function sub2() {
var    a, b, z;
. . .
}
. . .
}
function    sub3() {
var    a, x, w;
. . .
}

List all the variables, along with the program units where they are declared, that are visible in the bodies of sub1, sub2, and sub3, assuming static scoping is used.