1. Control structures to direct program flow
Loops
Control structures to direct program flow

2. Types of Loops
do loop - executed statements at least once. After execution of the previous statements, evaluate a condition to determine if the loop should be repeated.
do{ Statements;
}while(condition);

3. do Loop int value; do{ System.out.print(“Enter an integer > 0”);
value = in.nextInt();
} while(value>=0);

4. while loop
While loops evaluate a condition before execution of subsequent statements. While loops are event driven.
while(condition) {
statements; }

5. Using a sentinel A sentinel serves as a signal for termination.
int sentinel = -1;
while(!=sentinel) {
System.out.println(“hello”); }

6. For Loop are used for executing block statements a fixed number of times.
The condition is checked before each iteration
Initialization happens once before the loop starts
for(int i = 0; i<100; i+=50)
{ initialization Condition update
sum= sum + i; }
The update happens after each loop iteration

7. For loop example: for(int i=0; i<=5 i=i+1) { S.O.P(i+”,”); }
i at:
Result
Condition(i<=5)
true 1 2 3 4 5 6
No longer loops
false
for(int i=0; i<=5 i=i+1) { S.O.P(i+”,”); }
Result: 0,1,2,3,4,5