Description
- (8 points) Consider the C program given below. You will be asked to determine which variables are visible in a number of different situations. In each case, identify each variable by its name and the line number of its declaration.
- int h, i;
- void B(int w) {
- int j, k;
- i = 2*w;
- w = w+1;
- …
- }
- void A (int x, int y) {
- float i, j;
- B(h);
- i = 3;
- …
- }
- void main() {
- int a, b;
- h = 5; a = 3; b = 2;
- A(a, b);
- B(h);
- …
- }
- C uses static scoping. Say which identifiers (including variablesand function names) are visible in the bodies of each of the functions: main, A, B.
1
- If C used dynamic scoping and the calling sequence is main callsB. Say which identifiers would be visible in B.
- If C used dynamic scoping and the calling sequence is main callsA. Say which identifiers would be visible in A.
- If C used dynamic scoping and the calling sequence is main callsA; A calls B. Say which identifiers would be visible in B.
- (3 points) Find some online material to learn C++’s namespace mechanism. Explain briefly how it works and its benefits.
- (3 points) During the execution of a Java program, can a variable be visible but not allocated? Can a variable be allocated but not visible? Explain your answers.
