The document discusses different types of decision making and looping statements in C programming. It describes simple if, if-else, nested if-else, and else-if ladder statements for decision making. It also covers while, do-while, and for loops for iterative execution. Examples are provided for each statement type to illustrate their syntax and usage.

2.  The decision is describe to computer as a
conditional statement that can be answered true or false
 Since these statement control the flow of execution
they also known as control statements
 The if statement have different forms they are:
 Simple if statement
 If else statement
 Nested if else statement
 Else if ladder

3. SIMPLE IF STATEMENT
 if test expression is true the statement block
will be executed otherwise the statement block
will be skipped and the execution will jump to
next statement
Syntax
if(test expression )
{
statement block;
}
statement x;

4. Example program :
i= int(input(“Enter the number:”));
if (i<=10)
printf(“Condition is true”);
Output :
Enter the number:9
Condition is true
IF ELSE STATEMENT
 If test expression is true then true block
statement are executed otherwise false block
statement are executed not both block are executed
at same time.

5. Syntax :
if(test expression)
{
true block statement;
}
else
{
false block statement;
}
statement x;

6. printf("Enter your age:");
scanf("%d",&age);
if(age >=18)
{
printf("You are eligible for voting");
}
else
{
printf("You are not eligible for voting");
}
Output :
Enter your age:14
You are not eligible for voting

7. NESTED IF ELSE :
If condition 1 is false the statement 3 will be
executed otherwise it continue to perform
second test
if condition 2 is true the statement 1 will be
evaluated otherwise statement 2 will be
evaluated and then transferred to statement x

8. Syntax :
if(test condition 1)
{
if(test condition 2)
{
statement 1;
}
else
{
statement 2;
}
}
else
{
statement 3;
}
statement x;

9. Example program :
n=int(input(“Enter number:”));
if(n<=15)
if(n==10)
print(“Play volleyball”);
else
print(“Play cricket”);
else
print(“don’t play game”);
Output :
Enter number:10
Play volleyball

10. ELSE IF LADDER :
 The condition are evaluated from top of ladder
downwards.
As soon as a true condition is found the
statement associated with it is executed and the
control is transferred to the statement x.
When all n conditions become false then final
else containing the default statement will be
executed.

11. Syntax :
if(condition 1)
statement 1;
else if(condition 2)
statement 2;
else if(condition 3);
statement 3;
else if(condition n);
statement n;
else
default statement;
statement x;

12. Example program
a=int(input(“enter 1st number:”))
b=int(input(“enter 2nd number:”))
c=int(input(“enter 3rd number:”))
If(a>b)and(a>c)
print(“a is greater”)
Elseif(b<a)and(b<c)
print(“b is greater”)
Else
print(“c is greater”)
Output
enter 1st number:10
enter 2nd number:25
enter 3rd number:15
b is greater

13. DECISION MAKING AND LOOPING
 The test may be either to determine whether loop
has been repeated specified number of times or to
determine whether a particular condition has been
met
 The c language provides three constructs for
performing loop operations they are:
 While statement
 Do while statement
 For statement

14. The while is an entry controlled loop
statement
The test condition is evaluated and if
condition is true then the body of loop is
executed
After execution of the body the test
condition is once again evaluated and if it
is true the body is executed once again
The body of the loop may have one or
more statement

15. SYNTAX
while(test condition)
{
body of the loop
}
Example program
int count=1;
while(count<=4)
{
printf(“%d”,count);
count++;
}

16. OUTPUT
1 2 3 4
 The body of the loop may not be executed at all
if the condition is not satisfied at the very first
attempt
On some occasion to execute body of the loop
before the test is performed such situations can
be handled with the help of do statement

17. SYNTAX
Do
{
body of the loop
}
while(test condition);
Example program
int j=0;
do
{
printf("Value of variable j is: %dn", j);
j++;
}
while (j<=3);

18. OUTPUT
Value of variable j is: 0
Value of variable j is: 1
Value of variable j is: 2
Value of variable j is: 3
FOR LOOP
 The for loop is another entry controlled loop that
provides a more concise loop control structure
 initialization of control variables is done first
using assignment statement
 The value of control variable is tested using test
condition

19. SYNTAX
for(initialization;testcondition;increment)
{
body of the loop
}
Example program
int i;
for (i=1; i<=3; i++)
{
printf("%dn", i);
}
Output
1
2
3