Control Structures & Operator

Introduction of Control Structure

Statements are the instructions given to the computer to perform any kind of action, be it data movements, be it making decisions, or be in repeating action.

Various statements provided in C++ :

Selection statement

The selection statement allow you to choose the set of instructions for execution depending upon an expression value.

a) if-else statement:

It shows that the condition is checked in if statement if it returns the value true then it execute the statements inside the braces.

If it returns false value the automatically the statements in else condition are executed.

Syntax

if( expression )

{

statements;

}

else

{

statements;

}

program.

b) Switch statements:

C++ provides a multiple branch selection statements known as switch. This selection statement test the value of an expression against the value of the expression.

Syntax

switch(expression)

{

case 1:

case 2:

.........

}

Iteration statement

The iteration statements allows a set of instructions to be performed repeatedly until a certain condition to be fulfilled.

The iteration statements are also called looping statements. Some of the Iteration statement described here

a) The for loop:

The for loop is easiest to understand of the C++ loops. All its loop controls are gathered at one place.

Syntax

for( initialization, increment/decrement, termination condition)

{

.............

..........

}

b) The While loop:

The second Loop available in C++ is the while loop. The while loop is entry controlled loop.

Syntax

while(expression)

{

loop body

}

Jump statement

The jump statement unconditionally transfer the program control within a function. C++ has four statements that perform an unconditional branch.

a) The goto statement:

The goto statement can transfer a program control any where in the program. The target destination of goto statement is marked by a label.

Syntax

goto label;

:

:

label:

b) The Break statement:

The break statement enables a program to skip over part of the code. A break statement terminates the smallest enclosing while, do-while, for or switch statement.

Syntax

for(;;)

{

....

continue;

......

}

d) Exit statement:

Like break one can get out of the loop you can get out of the program by using a library function exit().

This function causes the program to terminate as soon as it encountered.