24.Conditional or turnery operators

 

Conditional or turnery operators:

?, : are two operators used to write the conditional statements.

The conditional statements are used in place of if-else control structure.

Conditional operators support two syntaxes

1. Statement
2. Expression

 

Sysntax1:

 

           

 

 

 

 

According to the above syntax if the condition is true then the first statement is executed, otherwise ststement2 is executed.

 

Specification1:

Accept any number and print whether the number is an even or odd.

 

In case of if-else   if(n%2==0)    printf("Even number"); else    printf("Odd number");

Program:

#include<stdio.h>

void main()

{

int n;

 

printf("Enter any number:");

scanf("%d",&n);

(n%2==0)?printf("Even number"):printf("Odd number");

 

}

 </code></pre>

Execution1:

Enter any number:25

Odd number

 

Execution2:

Enter any number:12

Even number

 

Specification2:

Accept any number and print whether the number is a zero, positive or negative.

 

Program:

#include<stdio.h>
void main()
{
int n;
printf("Enter any number:");
scanf("%d",&n);
(n==0)?printf("Zero"):((n>0)?printf(" Positive "):printf("Negative"));
Incase of if-else
if(n==0)
  printf("Zero);
else if(n>0)
  printf("Positive");
else
  printf("Negative");
}

Execution1:

Enter any number: 25

Positive

 

Execution2:

Enter any number: -14

Negative

 

Execution3:

Enter any number: 0

Zero

 

Syntax2:

 

 

 

 

 

 

 

According to the above syntax if the condition is true then the value of expression1 is assigned to the variable otherwise the value of expression2 is assigned to the variable.

 

Specification1:

Accept the price, quantity of a product and print the bill, discount and the net bill. Allow 5% discount if bill exceeds to 500 otherwise allow 3% discount.

 

In case of if-else   if(bill>500)    dis=bill*5/100; else    dis=bill*3/100;

Program:

#include<stdio.h>

void main()

{

float price,bill,dis,net_bill;

int qty;

 

printf("Price:");

scanf("%f",&price);

printf("Quantity:");

scanf("%d",&qty);

bill=price*qty;

dis=(bill>500)?bill*5/100:bill*3/100;

net_bill=bill-dis;

printf("Total bill %f",bill);

printf("\nDiscount %f",dis);

printf("\nNet bill %f",net_bill);

 

}

 </code></pre>

Execution1:

Price: 100

Quantity: 10

Total bill 1000.000000

Discount 50.000000

Net bill 950.000000

 

Points to remember:

 

1. In C language 0 is considered as false and any non-zero is considered as true.

Example:

#include<stdio.h>
void main()
{
printf("One");
if(10>40)
printf("\nTwo");
if(80<20);
printf("\nThree");
printf("\nFour");
}

Output:

One

Three

Six

 

2. If the "if control structure" is terminated with a semicolon then it can’t control the statement or block of statements under the conditional statement.

Example:

pava

Output:

One

Three

Four

 

Example explained:

Though (80<20) is false, it couldn’t control printf("\nThree"); because conditional statement is terminated with the semicolon.

 

3. Assigning (=) is different from comparison (==).

 

Example:

<pre><code>

#include&lt;stdio.h&gt;

void main()

{

int x=0,y=7;

 

if(y==1)

  printf("Hello");

if(x=5)

  printf("World");

 

}

 </code></pre>

Output:

World

 

Example explained:

(y==1) gives false hence printf("Hello"); is not executed.

x=5 assigns 5 to x and if(5) is true hence printf("World"); is executed.

 

4. Two nearby floating point constants can’t be compared because exact value may not be assigned to the variable.

 

Example:

<pre><code>

#include&lt;stdio.h&gt;

void main()

{

float x=0.4,y=0.7;

 

if(x<0.4)

  printf("Hello");

if(y<0.7)

  printf("World");

 

}

</code></pre>

Output:

World

 

Example explained:

0.4 is stored accurately into "x" hence (x<0.4) gives false and printf("Hello"); is not executed.

0.7 is stored approximately into "y" hence (x<0.7) gives true and printf("World"); is executed.