Do chapter 5 Problems

Description

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?

1. 1. 1. 1. sub1

1. 1. 2. sub2

1. 1. 2. 3. sub3

1. 2. 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.