do while loop
This (do while loop) statement is also used for looping. The body of this loop may
contain single statement or block of statement. The syntax for writing this
statement is:
Syntax:
Do
{
Statement;
}
while(condition);
Example:
#include
Output:
4 5 6 7 8 9 10
Here firstly statement inside body is executed then condition is checked. If the condition is true again body of loop is executed and this process continue until the condition becomes false. Unlike while loop semicolon is placed at the end of while.
There is minor difference between while and do while loop, while loop test the condition before executing any of the statement of loop. Whereas do while loop test condition after having executed the statement at least one within the loop.
If initial condition is false while loop would not executed it’s statement on other hand do while loop executed it’s statement at least once even If condition fails for first time. It means do while loop always executes at least once.
Notes: Do while loop used rarely when we want to execute a loop at least once
for loop
In a program, for loop is generally used when number of iteration are known in
advance. The body of the loop can be single statement or multiple statements. Its
syntax for writing is:
Syntax
for(exp1;exp2;exp3)
{
Statement;
}
or
for(initialized counter; test counter; update counter)
{
Statement;
}
Here exp1 is an initialization expression, exp2 is test expression or condition and
exp3 is an update expression. Expression 1 is executed only once when loop
started and used to initialize the loop variables. Condition expression generally
uses relational and logical operators. And updation part executed only when after
body of the loop is executed.
Example:-
void main()
{
int i;
for(i=1;i<10;i++)
{
Printf(“ %d ”, i);
}
}
Output
1 2 3 4 5 6 7 8 9
