Difference between revisions of "C-and-C++/C2/Nested-If-And-Switch-Statement/English"

Learning Objectives

nested if statement.

And

switch statements.

We will see this with the help of an examples.

System Requirements

Ubuntu operating system version 11.10

gcc and g++ Compiler version 4.6.1 on Ubuntu.

//Program to study nested if-switch loops

Note that our filename is nested-if.c

Let me explain the code now.

#include <stdio.h>

int main()

int x, y;

printf ("Enter an integer between the range of 1 to 29\n");

scanf("%d", &y);

We take the value of y as input from the user.

if(y/10==0)

{

printf("you have entered number between the range of 1-9\n");

}

Here we check the condition if y/10==0.

If the condition is true

We print "you have entered number between the range of 0-9.

else if(y/10==1)

{

printf("you have entered number between the range of 10-19\n");

}

Here, we check that y/10==1.

If the condition is true.

We print you have entered number in the range of 10-19.

else if(y/10==2)

{

printf("you have entered number between 20 to 29 \n");

}

{

printf("you have entered number between 30 to 39 \n");

}

{

printf("you have entered wrong number\n");

}

If all of the above conditions are false

We print number not in range.

return 0;

}

Please open the terminal window.

By pressing Ctrl+Alt+T simultaneously on your keyboard.

gcc nested-if.c -o nested

Type

./nested

Type “gcc” space “nested-if.c” space hyphen “-o”

space “nested”.

To execute the program,

type dot slash “./nested”

Press Enter.

Enter an integer between 0 to 39.

Let's enter 12.

Now Press Enter.

Output

you have entered a number between 10-19.

Let's execute again.

Press the up arrow key, press enter.

I will give 5 this time.

Output

you have entered a number between 0-9.

By using switch statement.

Let’s see how it is done.

I have already opened the program.

So I will move on to the switch statement.

x=y/10;

And the result will be stored in the variable x.

That means the quotient will be stored in x.

With the help of the quotient we can identify the range of the number.

switch(x)

{

case 0:

printf("you have entered a number in the range of 1-9\n");

If case 0 is satisfied.

We print you have entered a number in the range of 0-9.

We need to break the loop each time.

It is because only one condition can be true at a time.

case 1:

printf("you have entered a number in the range of 10-20\n");

break;

case 1 means, if the value of x is 1

We print you have entered a number in the range of 10-19.

case 2:

printf("you have entered a number in the range of 20-30\n");

break;

We print you have entered a number in the range of 20-29.

printf("you have entered a number in the range of 30-39\n");

Here we check whether the number in the range of 20-29.

default:

printf ("number not in range\n");

Default case specifies what needs to be done if none of the above cases are satisfied.

Here we print number not in range.

Compile.

Switch back to the terminal.

gcc switch.c -o switch

./switch

“gcc” space “switch.c” space hyphen “-o”

space “switch”.

Press Enter

Type: dot slash “./switch”

Press Enter

I will enter 35.

output

“you have entered the number between the range of 0 to 39”.

Note that our filename is nested-if.cpp

There are a few changes like:

The header file as iostream in place of stdio.h

using namespace std;

using namespace std

and scanf with cin

at all places

You can see that the rest of the code is similar to our C program.

Type:

g++ nested.cpp -o nested2

Type:

./nested2

Come back to the terminal.

Type:

g++ nested-if.cpp -o nested1

Press Enter

Type:

./nested1

Press Enter

Let's enter 40.

number not in range.

Come back to the text editor.

You can see that the header file is iostream.

Here is the using statement.

And we have changed the cout and cin function.

Rest of the code is similar to our switch.c program.

Press the up arrow, press enter.

Type:

g++ switch.cpp -o switch1

Press Enter

Type:

./switch1

Press Enter

I will enter 25.

The output is displayed as:

“you have entered number in the range of 20-29”.

We will see the comparison between nested-if and switch statement.

Comparison between switch

and if.

Nested-if statement is run only if the result of the expression is true .

In switch we treat various values of the variable as cases

Comparison between switch

and if.

Switch statement can only check the integer values .

Nested-if can check for both integer and fractional values .

This brings us to the end of this tutorial.

nested if statement.

Ex: else if(y/10==0)

switch statement.

Ex: switch(x)

Difference between nested-if and switch statements.

Assignment

Write a program to check whether the age of the employee is between 20-60

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