|
- Statement is executed first without testing any condition
- If the value of the -logical- expression is true, Statement is executed again
- If the value of the expression is false, execution continues at the statement immediately following the loop
do
{
Statement1;
Statement2;
...
StatementN;
} while (Expression);
- In the case of the while statement, the condition is tested in the beginning
- In the case of the do-while statement, the condition is tested at the end
- As a result, the body of the do-while statement will be executed at least one time !!!
- A looping control structure
- Simplifies the design of count-controlled loops
- Examples
for(count = 1; count <= 10; count++)
cout << count << endl;
for(count = 10; count <= 1; count--)
cout << count << endl;
for(InitStatement; LogicalExpression1; Expression2)
br
{
Statement1;
Statement2;
...
StatementN;
}
- It is used with the switch statement and with loop statements (i.e., while, for, do-while)
- It causes an immediate exit from the switch or from the loop
sum=0;
for (i=0; i<=10; i++)
{
cout << "Enter a number";
cin >> num;
if(num == -9999)
break;
sum = sum + num
}
- What if we have a nested loop statement ?
- break causes an immediate exit from the innermost loop only !!
sum=0;
for (i=0; i<=10; i++)
{
cout << "Enter a number";
cin >> num;
for(j=0; j<=10; j++)
{
if(sum > 1000)
break;
sum = sum * j * num;
}
}
- It is used with loop statements (i.e., while, for, do-while)
- It causes an immediate branch to the bottom of the loop
sum=0;
for (i=0; i<=10; i++)
{
cout << "Enter a number";
cin >> num;
if(num == -9999)
continue;
sum = sum + num
}
Recommended exercises
- Quick Check excersices: 1, 2, 3, 5
- Exam preparation excersices: 5, 6, 7, 9, 10, 11, 12