ABOUT FUNTION

#include<stdio.h>
void darab(void);
void tolak(int a,float b);
char zzz(void);
//------------------------------------------------------------------------------
int main()
{
    int a;
    float b;
    char kotak;
    a=10;
    b=5.5;
   
    darab();
    tolak(a,b);
    kotak = zzz();
    printf("%c",kotak);
    getchar();
    return (0);
}
//------------------------------------------------------------------------------
void darab(void)//get nothing return nothing
{
     int a, b, c;
     a=2;
     b=2;
     c=a*b;
     printf("total =a*b=%d\n",c);
     
}
//------------------------------------------------------------------------------
void tolak(int a,float b)//get something return nothing
{
     float sum;
     sum=a-b;
     printf("total =a-b=%.2f\n",sum);
     //xpayah letak return (0); sbb dye return nothing
}
//------------------------------------------------------------------------------
char zzz(void)//get nothing return something
{
     return('a');
}

Chapter 4-Loops

There are 4 loops :

• The while loops
• The do-while loops
• The for loops
• The odd loops 

Definiton of loops:
->Loops is use to repeat a program so that we do not need to re-write the coding again and again.

•There are three methods by way of which we can repeat a part of a program. They are:

–(a) Using a while statement

–(b) Using a for statement

–(c) Using a do-while statement

The while loop:

initialize loop counter ;

while ( test condition )

{

  do this ;

  and this ;

  increment loop counter ;

}

The do-while loop:

do

{

this ; 

and this ;

and this ; 

and this ; 

} 

while ( this condition is true ) ;

Do-while loop will still run even the first time is an error. 

The for loops:

for ( initialize counter; test counter; increment counter

  )

{

  do this ;

  and this ;

}

The odd loops:

 example of odd loop

#include <stdio.h>
int main(void )
{
    char another ;
    int num ;
    do
    {
        printf ( "Enter a number " ) ;
        scanf ( "%d", &num ) ;
        printf ( "square of %d is %d", num, num * num ) ;
        printf ( "\nWant to enter another number y/n " ) ;
        scanf ( " %c", &another ) ;
    } while ( another == 'y' ) ;
} 

 

  the output is:

 

thats the end of chapter 4...

   

Chapter 3-Switch case

SWITCH CASE:
decisions using switch case

#include <stdio.h>
int main ( )
{
    int marks,status;
    printf("\nEnter marks = ");
    scanf("%d",&marks);
   
    if (marks > 79 && marks < 100)
    printf("\nA,Pass\n");
    else if(marks > 60 && marks < 79)
    printf("\nB,Pass\n");
    else if(marks > 40 && marks < 59)
    printf("\nC,Pass\n");
    else
    printf("\nF,Fail\n");
    scanf("%d",&marks);
return 0;
}


example of switch case..:

void main(void)

{

int i = 2 ;

switch ( i )

{

case 1 :

printf ( "I am in case 1 \n" ) ;

break ;

case 2 :

printf ( "I am in case 2 \n" ) ;

break ;

case 3 :

printf ( "I am in case 3 \n" ) ;

break ;

default :

printf ( "I am in default \n" ) ;

}

}

and the flowchart:

and this is my example:

#include<stdio.h>
int main(void)
{
    int select,area,w,h;
    printf("**********program to calculate area rectangle********\n");
    printf("*              please select an option                                      *\n");
    printf("*                                                                                        *\n");
    printf("*                  1.rectangle                                                     *\n");
    printf("*                   2.exit                                                             *\n");
    printf("**********************************************\n");
   
    scanf("\n%d,",&select);
   
       switch(select)
       {
                     case 1:
                     printf("program to calculate rectangle\n");
                     //printf("calculate the area of rectangle");
                     printf("key in the width for calculation = ");
                     scanf("\n%d",&w);
                     printf("key in the height for calculation = ");
                     scanf("\n%d",&h);
                     area=w*h;
                     goto answer;
                     break;
                     default:
                     printf("wrong case selelcted!!!");
                     goto exit;
       }
       answer:printf("the area is = %d\n",area);
       exit:;
       scanf("\n%d,",&select);
       }

Logical Operators

•C allows usage of three logical operators, namely, &&, || and !. These are to be read as

  ‘AND’ ‘OR’ and ‘NOT’ respectively.

 

•Don’t use the single symbol | and &. These single symbols also have a meaning. They are bitwise operators

example question:

•Example 2.4 : The marks obtained by a student in 5 different subjects are input through the keyboard. The student gets a division as per the following rules:

Percentage above or equal to 60   - First division

Percentage between 50 and 59   - Second division

Percentage between 40 and 49   - Third division

Percentage less than 40   - Fail

so the coding are as follow:

#include <stdio.h>
int main ( )
{
    int marks,status;
    printf("\nEnter marks = ");
    scanf("%d",&marks);
   
    if (marks > 79 && marks < 100)
    printf("\nA,Pass\n");
    else if(marks > 60 && marks < 79)
    printf("\nB,Pass\n");
    else if(marks > 40 && marks < 59)
    printf("\nC,Pass\n");
    else
    printf("\nF,Fail\n");
    scanf("%d",&marks);
return 0;
}

 

The If Else statement

•to execute one group of statements if the expression evaluates to true and another group of statements if the expression evaluates to false

example:

•If his basic salary is less than RM 1500, then HRA = 10% of basic salary and DA = 90% of basic salary. If his salary is either equal to or above RM 1500, then HRA = RM 500 and DA = 98% of basic salary. If the employee's salary is input through the keyboard write a program to find his gross salary.

so the coding is as follow:

#include <stdio.h>
int main(void)
{
    int basicsallary, a, aa, sallary, sallaries;
    // get input
    printf("\nplease enter your basic sallary=");
    scanf("%d",&basicsallary);
    a = basicsallary - (0.1*basicsallary);
    aa = basicsallary - 100 ;
    sallary = a + 500 ;
    sallaries = aa + 800 ;
   
    //condition
                 if (basicsallary > 1500)
                 {
                  printf("your new basic sallary is = %d", a);
                 }
                 if (basicsallary < 1500)
                 {
                  printf("your new basic sallary is = %d,aa");
                 }
                 if (a > 3000)
                 {
                 printf("your new total sallary is = %d", sallary);
                 }
                 if(aa < 3000)
                 {
                 printf("your new total sallary is = %d",sallaries);
                 }
                  scanf("%d",&basicsallary);  
                 
return 0;          
}

NUMBER 1 chapter 2

•Many a times, we want a set of instructions to be executed in one situation, and an entirely different set of instructions to be executed in another situation.

 

•a decision control instruction can be implemented in C using:

–The if statement

–The if-else statement

 

    –The conditional operators

 Example of flowchart

example of coding:

#include <stdio.h>
int main (void)
{
     int jyear,cyear,serv;
     printf("please enter your join year=\n");
     scanf("%d",&jyear);
     printf("please enter the year now=\n");
     scanf("%d",&cyear);
     serv = cyear - jyear;
     if(serv>3)
     {
               printf("wahhhh dapat bonus!!\n");
     }
     scanf("%d",&jyear);
return 0;
}   

 

CHAPTER 2

CONSIST OF:

1-Decisions!decisions!
2-The If statement
3-The If-Else statement
4-A word of caution
5-The conditional operators