c sharp jn (3)
TRANSCRIPT
Software Development Training Program
Zeeshan Hanif
Random Numbers .Net Framework provide a class Random
in System namespace that can be used to generate random numbers.
Random r = new Random(); int a = r.Next(); Console.WriteLine(a); any random number maximum of Int32
size
Random Numbers Methods
Next(); Return an integer grater than or
equal to zero and less than Int32 maximum size.
Next(maxValue);Return an integer grater then or
equal to zero and less then maxValue
Random Numbers Methods
Next(minValue,maxValue);Return an integer grater then
or equal to minValue and less then or equal to maxValue
r.Next();r.Next(10);
r.Next(5,10);
Boolean expressions Expressions that have a boolean
result Relational Operators
== - equal to != - not equal to > - greater than >= - greater than or equal to < - less than <= - less than or equal to
Boolean operators
Boolean AND (&) Boolean OR (|) && and ||
Control Statements
Without control structures C# code executes in a sequential fashion. Every statement executes sequentially and if you want to skip any statement you can not do so.
start
end
Statement 1
Statement 1
Statement 1
If StatementStart
Statements
IF
If block statements
Statements
truefals
e
End
If Conditionpublic void main(string[] args){
int a=10;……Console.WriteLine(“Before if condition”);if(a>10){
Console.WriteLine(“A is greater than 10”);}Console.WriteLine(“After if condition”);……
}
if and elsepublic void main(string[] args){
int a=10;Console.WriteLine(“Before if condition”);if(a>10){
Console.WriteLine(“A is greater than 10”);}else {
Console.WriteLine(“A is less than 10”);}Console.WriteLine(“After if condition”);
}
Nested ‘if’ statementspublic void main(String[] args){
int a = 11, b = 5;if (b<10) { //First if condition Console.WriteLine(“Inside first if”);if(a>10) { //Nested if conditionConsole.WriteLine(“Inside Second if”);}Console.WriteLine(“After second if condition”);}
Console.WriteLine(“After First if condition”);}
Matching Nested if and elsepublic void main(String[] args){
int a=11,b=5;if(b<10) {
Console.WriteLine (“Inside first if”);if(a>10)
Console.WriteLine(“Inside second if”);else
Console.WriteLine(“Else of second if”);}else Console.WriteLine(“Else of first if”);
}
else-ifpublic void main(string[] args){
int a=10;Console.WriteLine(“Before if condition”);if(a>10){
Console.WriteLine(“A is greater than 10”);}else if(a>5){
Console.WriteLine(“A is greater than 5 but less then 10”);}else {
Console.WriteLine(“A is less than 5”); }
Console.WriteLine(“After if condition”);}
Switch statement
Switch statement is ideal for testing a single expression against a series of possible values and executing the code associated with the matching case statement. If any of the case does not match then the optional default statement is executed.
Switch Structure
Condition Statementstrue
false
Statements
Condition Statements
false
true
break
break
Switch statementswitch(op){
case value1:(statements)break;
case value2:(statements)break;
case value3:(statements)break;
default:(statements)break;
}
Switch statementint a = 5;switch(a){
case 2:Console.WriteLine(“Number is 2”);break;
case 5:Console.WriteLine(“Number is 5”);break;
default:Console.WriteLine(“Not Matched”);break;
}
For loop
The for loop provides a means to repeat a section of code a designated number of times. The for loop is structured so that a section of code is repeated until some limit has been reached.
initialize
Condition Statements
false
trueInc / dec
For structure
For loop
public static void main(String[] args){
…..for(<init block> ; <condition> ; <increment>){
<statement(s)>}….
}
Example
public static void main(String[] args){
…..for(int a=0 ; a<10 ; a++){
Console.WriteLine(“A = “+a);}
}Result of a ten times
while Statement
Like the for loop, the while loop has a loop condition that controls the execution of the loop statement. If the boolean condition evaluates to true, the Statement is executed and the process starts over
while Structure
Condition Statements
false
true
While loop
public static void main(String[] args){
…..while(<condition>){
<statement(s)>}….
}
Examplepublic static void main(string[] args){
…..int a = 1;while ( a < 10 ){ Console.WriteLine(a); a++;}…..
}
While loop
The important thing to notice about the while loop is that its condition occurs before the body of the loop Statement. This means that if the condition initially evaluates to false, the Statement is never executed.
do-while Statement
The do-while loop is very similar to the while loop, The major difference between the do-while loop and the while loop is that a do-while loop is guaranteed to execute at least once.
do-while Structure
Statements
Condition
false
true
do-whilepublic static void main(String[] args){
…..do{
<statement(s)>} while(<condition>);….
}
do-while
The Statement is executed initially, and from then on it is executed as long as the condition evaluates to true.
Examplepublic static void main(string[] args){
…..int a = 1;do{ Console.WriteLine(a);
a++;} while ( a < 10 );…..
}
‘break’ and ‘continue’
‘break’: used to terminate and jump out of the loop
‘continue’: jumps to the next iteration of the loop
Example (break)
for(int i = 0 ;i<10;i++){ if(i==5)
break; Console.WriteLine(i);}Result :0,1,2,3,4
Example (continue)
for(int i = 0 ;i<10;i++){ if(i==5)
continue; Console.WriteLine(i);}Result :0,1,2,3,4,6,7,8,9
Nested loopspublic static void main(string[] args){
…..for(<init block> ; <condition> ; <increment>){
for(<init block> ; <condition> ; <increment>)
{<statement(s)>
} //end of inner for loop } //end of outer for loop ….
}
Nested loopsfor(int i=0 ; i<3 ; i++){
for(int j=0 ; j<2 ; j++){
Console.WriteLine(“I = “+i+”, J = “+j);} //end of inner for loop
} //end of outer for loop Result:I = 0, J = 0I = 0, J = 1I = 1, J = 0I = 1, J = 1I = 2, J = 0I = 2, J = 1
Examples
Print the greatest among three nos. Print the table of 2 and 3
simultaneously Factorial of a given no. Finding prime nos.
Examples
Exercise Write an application that creates a random number integer between 0 and 10. Then use a nested if to print out whether that number is between 0 and 2, 3 and 5, 6 and 8, 9 and 10.
Examples
Exercise :Write a program that acts as a calculator for balancing a check book. It should take an initial balance and then a sequence of deposits and withdrawals. When done the program should print the final balance.
Examples Write a program that prints the
following pattern. Your solution must use a loop. * * * * * * * * * * * * * * *
Example Exercise : Write a program that simulates
rolling a pair of dice until the total on the dice comes up to be a given number. The number that you are rolling for is fixed in a variable. The number of times you have to roll the dice is the output of the program. You can assume that the parameter is one of the possible totals: 2, 3, ..., 12. Use your program that computes and prints the number of rolls it takes to get snake eyes. (Snake eyes means that the total showing on the dice is 2.)