1. Parameter Passing & Array Examples – Part 1
Chalermsak Chatdokmaiprai
Computer and Programming
Department of Computer Engineering Kasetsart University
Cliparts are taken from

2. Example 1 Program's Stack Space output Main()'s Stack i 10 8 j 50 14
class MyClass { public static void Main () { int i = 10; int j = Foo( i, i+5 ); Console.WriteLine("{0},{1}", i, j); Console.WriteLine("{0},{1}", Bar(6, out i), i); } static int Foo (int x, int y) { int i; x = Bar( x, out i ) + 1; return x + y + i; static int Bar (int j, out int k) { k = j + 2; return j + k; i 10 8 j 50 50 10 15 14 50
Bar()'s Stack
Foo()'s Stack j x 10 6 23 14 6 8 k y 15 i 12 22 10 23 1 22
Bar()'s Stack j 10 23 50 15 12 k 10 6 12 8 2
output 10 22 12
10,50
14,8 6 14 8

3. Example 2 Program's Stack Space output
using C=System.Console; class MyClass { static void Main () { int i = 22; C.WriteLine("At A: {0}", i); AlterInt(i); C.WriteLine("At B: {0}", i); } static void AlterInt (int i) { C.WriteLine("At C: {0}", i); i = 55; C.WriteLine("At D: {0}", i);
Main()'s Stack i 22
AlterInt()'s Stack i 55 22
output
At A: 22
At C: 22
At D: 55
At B: 22

4. Example 3
using C=System.Console; class MyClass { static void Main () { int[] i = new int[2] {22, 99}; C.WriteLine("At A: {0}", i[0]); AlterInt(i); C.WriteLine("At B: {0}", i[0]); } static void AlterInt (int[] i) { C.WriteLine("At C: {0}", i[0]); i[0] = 55; C.WriteLine("At D: {0}", i[0]);
output
At A: 22
At C: 22
At D: 55
At B: 55

5. Array Example
Program's Stack
Program's Heap
Main()'s Stack
[0]
[1]
using C=System.Console; class MyClass { static void Main () { double[] a; //uninitialized a = null; //initialized to null a = new double[2];//allocated double[] b = new double[] {1.1, 2.2, 3.3}; a = b; int m = (int) a[1]; b[(m*10)%3] = b[m-1] + 10; C.WriteLine("{0}, {1}, {2}", a[0],a[1],a[2]); } a
garbage b
[0]
1.1
[1]
2.2
[2]
3.3 m 2
12.2
output 2
b[2]
12.2
1.1, 2.2, 12.2
2.2 10

6. Example 3 dissected output Program's Stack Program's Heap
using C=System.Console; class MyClass { static void Main () { int[] i = new int[2] {22, 99} ; C.WriteLine("At A: {0}", i[0]); AlterInt(i); C.WriteLine("At B: {0}", i[0]); } static void AlterInt (int[] i) { C.WriteLine("At C: {0}", i[0]); i[0] = 55; C.WriteLine("At D: {0}", i[0]);
Program's Stack
Program's Heap
Main()'s Stack i =
AlterInt()'s Stack
[0]
[1] 55 22 i 99
output
At A: 22
At C: 22
At D: 55
At B: 55

7. Example 3 plus output Program's Stack Program's Heap
using C=System.Console; class MyClass { static void Main () { int[] i = new int[2] {22, 99} ; C.WriteLine("At A: {0}", i[0]); AlterInt(i); C.WriteLine("At B: {0}", i[0]); } static void AlterInt (int[] i) { C.WriteLine("At C: {0}", i[0]); i[0] = 55; C.WriteLine("At D: {0}", i[0]); i = new int[3] {66,77,88}; C.WriteLine("At E: {0}", i[0]);
Program's Stack
Program's Heap
Main()'s Stack i =
AlterInt()'s Stack
[0]
[1] 55 22 i 99
[0] 66
[1] 77
[2] 88
output i=
At A: 22
At C: 22
At D: 55
At E: 66
At B: 55

8. Example 4 a output Stack Heap i 55 66 k 99 n 10 3 20 x 30 i 2 1 3
Main()
using C=System.Console; class MyClass { static void Main () { int[] i = new int[2] {55,66}; i[0], i[1]); int[] k = i; k[1] = 99; i[0], i[1]); i = GetData(3); i[0], i[1], i[2]); k[0], k[1]); } static int[] GetData (int n) { int[] x = new int[n]; for (int i = 0; i < n; i++) x[i] = (i+1)*10; x[0], x[1], x[2]); return x; i
[0] 55
[1] 66 k 99
GetData()
[0]
[1]
[2] n 10 3 20 x 30 i 2 1 3
output
@A:i=55,66
@B:i=55,99
@E:x=10,20,30
@C:i=10,20,30
@D:k=55,99

9. Example 4 b Example 4 a output Stack Heap i 55 66 k 99 n 10 3 20 x 30
Main()
using C=System.Console; class MyClass { static void Main () { int[] i = new int[2] {55,66}; i[0], i[1]); int[] k = i; k[1] = 99; i[0], i[1]); GetData(3, out i); i[0], i[1], i[2]); k[0], k[1]); } static void GetData (int n, out int[] x) { x = new int[n]; for (int i = 0; i < n; i++) x[i] = (i+1)*10; x[0], x[1], x[2]); i
[0] 55
[1] 66 k 99
GetData()
[0]
[1]
[2] n 10 3 20 x 30
Example 4 a i 3 1 2
i = GetData(3); }
static int[] GetData (int n) {
int[] x = new int[n];
for (int i = 0; i < n; i++)
x[i] = (i+1)*10;
return x;
output
@A:i=55,66
@B:i=55,99
@E:x=10,20,30
@C:i=10,20,30
@D:k=55,99

10. The End