Conditional Statements Cont.

salamo3alikom everyone :)

Last session we take the conditional statement if and the logical operators and /or
in this session we will practice on how to use if condition and logical operators.

Session Agenda:

1. Practice on if condition and Logical operators.

let's start with last session practice :
write a program that takes two numbers and always print the bigger one :).

solution :

#include<stdio.h>

int main()

{

    int N1, N2;

   printf("Please Enter Two Numbers\n");

  scanf("%d%d",&N1,&N2);

  

  if(N1>N2)  

          printf("%d\n",N1);

  if(N2>N1)

          printf("%d\n",N2);

   return 0;

}

 
 let's take a look about this solution :

if(N1>N2)  

          printf("%d\n",N1);

why we didn't put {   } after the if condition as we said before ?
if you have only one operation there is no need to put {} as if implements automatically the first line below it.

but if you have multiple operations you need to put {} like this :

if(N1>N2)  

{

          printf("%d\n",N1);

          printf("another statements\n");

//some code

}

ELSE Statement
what is the possible comparisons between two numbers?

Number 1 bigger than Number 2
Number 1 smaller than Number 2
Number 1 equal to Number 2

okay so if N1 is  bigger than N2  we will print N1 but if N1 is smaller or even equal we need to print N2 right ?

well we will modify the previous program to be much simpler to be like this:

#include<stdio.h>

int main()

{

    int N1, N2;

   printf("Please Enter Two Numbers\n");

  scanf("%d%d",&N1,&N2);

  

  if(N1>N2)  

          printf("%d\n",N1);

  else                            //else statement used if you don't care about other conditions

          printf("%d\n",N2);

   return 0;

}

this means print N1 if it was bigger and print N2 if the first condition failed. 

Practice 2:

write a program that takes a number from user and check if it was even or odd number.

Even & Odd:

1. Even Number a number who is divisible by 2.
2. Odd Number a number who isn't divisible by 2.

sample input :
2
output:
Even

sample input :
5
Output:
Odd

#include<stdio.h>

int main()

{

    int x;

   printf("Please Enter a number\n");

  scanf("%d",&x);

  

  if(x%2==0)  

          printf("Even\n");

  else           

          printf("Odd\n");

   return 0;

}

Practice 3:

Write a program that takes a number and check if it was a multiple of three or not.

• multiple of three ==> is divisible by 3.

sample input :
9
output :
Yes

sample input :
20
output:
No

#include<stdio.h>

int main()

{

    int x;

   printf("Please Enter a number\n");

  scanf("%d",&x);

  

  if(x%3==0)  

          printf("Yes\n");

  else           

          printf("No\n");

   return 0;

}

Practice 4:

Write a Program that takes Three numbers and print them sorted.

sample input:
5 1 2
output :
1 2 5

sample input:
6 1 8
output:
1 6 8

#include<stdio.h>

int main()

{

    int x,y,z;

   printf("Please Enter Three number\n");

  scanf("%d%d%d",&x,&y,&z);

  

  if(x<=y && y<=z)

          printf("%d %d %d\n",x,y,z);

  else if(x<=z && z<=y)                        // this means if first one didn't occur check me

          printf("%d %d %d\n",x,z,y);

 else if(y<=x && x<=z)      

          printf("%d %d %d\n",y,x,z); 

 else if(y<=z && z<=x)       

          printf("%d %d %d\n",y,z,x);

 else if(z<=x && x<=y)        

          printf("%d %d %d\n",z,x,y);

 else if(z<=y && y<=x)        

          printf("%d %d %d\n",z,y,x);

    return 0;

}

what is the difference between multiple if like that:
if(condition 1 )
     do task 1;
if (condition 2)
     do task 2; 
.........
.......
this means each time you are going to  check all conditions.
but if you made it like that :

if(condition 1 )
     do task 1;
else if (condition 2)
     do task 2;  
you will check condition1 one if succeeded you won't check condition 2.
so you don't need to pass through all conditions since you got your condition.


i hope you enjoyed this session :) thanks so much salamo3alikom.