core

1. HaNoi University of Technology Week 2:Core C# Programming Constructs – Mastering C# 2008
Week 2: Core C# Programming Constructs
Topics
• Constants & Variable
• Statements and Expressions
• Control Flow
PART I: C # BASIC
Exercise 1
Which letters represent valid identifiers?
a) Abc e) $$$ i) a_1
b) M/H f) 25or6to4 j) Student Number
c) Main g) 1_time k) string
d) double h) first-Name
Valid identifiers are ______________________________________________
Invalid identifiers are ____________________________________________
Exercise 2
using System;
class Class1
{
static void Main()
{
const int y = 1,z = 2;
const string x = "Hello";
string X = "World";
Console.WriteLine(y + z);
Console.WriteLine(x + " " + X);
Console.ReadLine();
}
}
2.1 What is written by this program?
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2. HaNoi University of Technology Week 2:Core C# Programming Constructs – Mastering C# 2008
2.2 List all variables in this program.
Exercise 3
using System;
class Class1
{
static void Main()
{
const int b=a+1; //1
const int d=c+3; //2
const int c=b+2; //3
const int a=1; //4
Console.WriteLine(a + b + c + d);
Console.ReadLine();
}
}
3.1 From this program, when compiled, there are some errors. Why?
3.2 This program can be corrected by rearrangement of lines (1) to (4).
Rewrite CONSTANT DECLARATION PART of this program to correct it.
________________________
________________________
________________________
________________________
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3. HaNoi University of Technology Week 2:Core C# Programming Constructs – Mastering C# 2008
Exercise 4
static void Main()
{
string s = "abc"; //1
int n = 0; //2
double x = 0.0; //3
s = n; //4
n = 1.0; //5
n = x; //6
x = 999; //7
x += n; //8
s = "abc" + 1; //9
s -= 1; //10
n = 1 + 1.5; //11
}
In which line of this program (4-11) did errors occur?
Line The problem is …
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4. HaNoi University of Technology Week 2:Core C# Programming Constructs – Mastering C# 2008
PART II: Operators and Priorities
Precedence Order Operator
1 ()
2 ++(x),--(x),+(x),-(x)
3 *,/,%
4 +,-
5 =,+=,-=,*=,/=,%=
6 (x)++,(x)--
Exercise 5
class Test
{
static void Main()
{
double x = 3.0, y = 2.0;
int a = 10, b = 2;
(1)
Console.ReadLine();
}
}
Insert the line numbered (1) using instructions from the following table.
Fill the column output.
(1) Output
Console.WriteLine(x+a);
Console.WriteLine(a/b);
Console.WriteLine(y/x);
Console.WriteLine(y%x);
Console.WriteLine(++y%x-1);
Console.WriteLine(y--%x+1);
Console.WriteLine(a+b%b);
Console.WriteLine(x/y*b);
Console.WriteLine((a+b)/b%a);
Console.WriteLine(9.0/5.0*(a-x));
Console.WriteLine(x+y-x*y%x);
Console.WriteLine(57%50/25);
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5. HaNoi University of Technology Week 2:Core C# Programming Constructs – Mastering C# 2008
PART III: Control Flow
Exercise 6
class IfElseStruct
{
static void Main()
{
int x = 15;
int y=20 ;
if(x>y)Console.WriteLine(x);
else Console.WriteLine(y) ;
Console.ReadLine();
}
}
What is written from this program?
Exercise 7
class ForStruct
{
static void Main()
{
for(int i=1 ;i<10 ;i++){
Console.WriteLine(i*i);
}
Console.ReadLine();
}
}
What is written from this program?
Exercise 8
using System;
{
class WhileStruct
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6. HaNoi University of Technology Week 2:Core C# Programming Constructs – Mastering C# 2008
{
static void Main()
{
int n=10;
while(true){
if(n>0){
Console.WriteLine(n);
n--;
}
else break;
}
Console.ReadLine();
}
}
}
What is written from this program?
Exercise 9
using System;
{
class Foreach
{
static void Main()
{
int[] A={10,9,8,7,6,5,4,3,2,1};
foreach(var x in A){
Console.WriteLine(x);
}
Console.ReadLine();
}
}
}
What is written from this program?
6/6

7. HaNoi University of Technology Week 2:Core C# Programming Constructs – Mastering C# 2008
{
static void Main()
{
int n=10;
while(true){
if(n>0){
Console.WriteLine(n);
n--;
}
else break;
}
Console.ReadLine();
}
}
}
What is written from this program?
Exercise 9
using System;
{
class Foreach
{
static void Main()
{
int[] A={10,9,8,7,6,5,4,3,2,1};
foreach(var x in A){
Console.WriteLine(x);
}
Console.ReadLine();
}
}
}
What is written from this program?
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