Some more Control statements

C Tutorial, Control Statement / By
The break Statement
We have already met break in the discussion of the switch statement. It is used to exit from a loop or a switch, passing control to the first statement beyond the loop or a switch.
With loops, break can be used to force an early exit from the loop, or to implement a loop with a test to exit in the middle of the loop body.
A break within a loop should always be protected within an if statement which provides the test to control the exit condition.
An Example program to determine whether a number is prime or not:
Out put of the program
The continue Statement
This is similar to break but is encountered less frequently. It only works within loops where its effect is to force an immediate jump to the loop control statement.
In a while loop, jump to the test statement.
In a do while loop, jump to the test statement.
In a for loop, jump to the test, and perform the iteration (looping).
Like a break, continue should be protected by an if statement. You are unlikely to use it very often.
An example of program using continue statement:
Out put of the program
The goto Statement
C has a goto statement which permits unstructured jumps to be made. It requires a label in order to identify the place where the branch is to be made.
A label is any valid variable name,and must be followed by a colon(:).
Syntax:
goto label;
………………
label:
statement;
The label can be any where in the program either before or after the goto label; statement.
An example program using goto statement:
Out put of the program
Explanation of the program
Here the program will ask untill you give negative value at the time when you give positive value then instantly it will show you the square root value of the given number.
Another use of the goto statement is to transfer the control out of a loop (or nested loops) when certain particular conditions are encountered.
Note: We should try to avoid using goto as far as possible because, it is not good for readability of the program or to improve the program execution speed.
The exit() function
This function is used for terminating the execution of C program.
Syntax:
exit(int status);