Explanation of Local and Global Variables with Example

Local and Global variables:

Local variables: 

Variable whose existence is known only to the main program or functions are called local variables. Local variables are declared with in the main program or a function.

Global variables: 

Variables whose existence is known to the both main() as well as other functions are called global variables. Global variables are declared outside the main() and other functions.

The following Program illustrates the concept of both local as well as global variables.

Statement of C Program: This program does not accept anything from the keyboard. It initialises the variables a to 10 outside the main() function and value().

#include<stdio.h>

int a = 10;                                 /* global declaration */

main()

{

int b;

printf("  = %d\n" , i);

b = value(i)

printf(" j = %d\n");

}                                                              /* End of main() */

                    /* Function to compute value */

int value(i)

int i;

{

int c;

c = i + 10;

return(c);

}                                           /* End of Function */

Output:

 i = 10

 b = 20

Explanation:

The statement int  i = 10;   that appears before the main() is a global declaration. The value of i is accessed by the main program as well as the function value(). The variable c is local to the function value(). It has no existence in the function value(). The variable b is also local to the main() but has no scope in the function value().

                                                                  That's All

WAP of C Language that illustrates the Function with no arguments and no Return values

Functions with no Arguments and no Return values:

The called Function does not receive any data from the calling Function and it does not return any data back to the calling Function. Hence, there is no data transfer between the calling Function and called Function. So, let us understand this with the help of Program:

Statement of C Program: This Program illustrates the Function with no Arguments and no Return value:

#include<stdio.h>

#include<conio.h>

void main()

{

read_value();

}

read_value()

{

char name[10];

printf(" Enter your name\n");

scanf("%s" , name);

printf(" Your name is %s , name);

}

Output:

Enter your name

shubham

Your name is shubham

                                                                  That's All

WAP of C Language that illustrates the Function with no Arguments and Return values

Functions with no Arguments and Return value:

The called Function does not recieve any data from the calling Function. It is also a one-way data communication between the calling Function and the called Function. So let us understand this with the help of Program:

Statement of C Program: This Program illustrates the Function with no Arguments and Return values:

#include<stdio.h>

#include<conio.h>

void main()

{

float sum;

float total();

clrscr();

sum = total();

printf(" Sum = %f\n" , sum);

}

float total()

{

float a, b;

a = 5.0 ;

b = 15.0 ;

return(a+b);

}

Output:

Sum = 20.000000

                                                                    That's All

Detailed Discription of Category of Functions with Examples

Category of Functions:

We have some other type of Functions where arguments and return value may be present or absent. Such functions can be categorised into:

1. Function with arguments but no return value.
2. Function with no arguments and return value.
3. Functions with no arguments and no return values

So Let's have a look on Category of Functions one by one:

1. Function with Arguments but no return value: 

Here the called Function recieves the data from the calling function but the called function does not return any value back to the calling Function.So, let us understand with the help of Program:

Statement of C Program: This Program illustrates the Function with arguments but no return value:

#include<stdio.h>

#include<conio.h>

void main()

{

int a, b;

printf(" Enter the value of a and b\n");

scanf("%d%d" , &a ,&b);

largest(a, b);

}

/* Function to compute largest */

largest(c, d)

int c, d;

{

if(c>d)

{

printf(" Largest = %d\n");

}

else                                                    /* (c<d) */

{

printf(" Largest = %d\n");

}

return();

}

Output:

Enter the values of a and b

20

15

Largest = 20

Function with no Arguments and Return Values

Functions with no Arguments and no Return Values

WAP of C Languge Function that Calculates the Square of a accepted number

Arguments and Parameters:

Arguments and parameters are variables used in a Function. Variables used in a Function calling( Function reference) are called Arguments. These are written within the parentheses followed by the name of the Function.

Variables used in the Function definition are called Parameters. Parameters must be written within the parenthesis followed by the name of the Function, in the Function Definition.So let us understand Parameters and Arguments with the help of Program.

Statement of C Program: This program accepts a Number and prints its Square.

#include<stdio.h>

#include<conio.h>

void square(int i);                                   /* Function Declaration */

void main()

{

int a;

clrscr();

printf(" Enter the value of a\n");

scanf("%d" , &a);

square(a);                                                  /* Function calling */

getch();

}

void square( int i )                                   /* Function Definition*/

{

int b;

b= i*i;

printf(" square = %d\n" , b);

}

Output:

Enter the value of a

2

square = 4

                                                                   That's All

Important points about C Language Function

We know that Function is very Important part of C Language. With the help of Function Programs are easy to write and understand. So there are some Key points to remember when deal with C Language Function: 

• A Function gets called when the Function name is followed by a semicolon(;).

Example:

int main()

{

india();                 /* Function calling */

}

•  A Function can call itself. Such a process is called "recursion". Discuss later.

---

• A Function can be called from another Function, but a Function cannot be defined in another Function.

Example:

int main()

{

printf(" Hello");

void india()                                /* Function definition */

{

printf(" I am in India");

}

The above Program code would be wrong because india() is being defined inside another Function main().

---

• A Function can be called any number of times.

Example:

#include<stdio.h>

void india();                          /* Function Declaration */

int main()

{

india();                                 /* Function Calling */

india();                                 /* Function Calling */

return(0);

}

void india()                           /* Function Definition */

{

printf(" Hello\n");

}

---

• The order in which the Functions are defined in a Program and the order in which they get called need not necessarily be same.

Example:

#include<stdio.h>

void India();                                      /* Function Declaration */

void England();                                  /* Function Declaration */

int main()

{

India();                                             /* Function Calling */

England();                                         /* Function Calling */

return(0);

}

void England()                                   /* Function Definition */

{

printf(" Olympic games");   

}

void India()                                        /* Function Definition */

{

printf(" Beautiful city of corruption");

}

India() is getting called before England(), still India() has been defined after England().

---

• Any Function can be called from any other Function.

Example:

#include<stdio.h>

void India();                         /* Function Declaration */

int main()

{

India();                                /* Function Calling */

return(0);

}

void India()                          /* Function Definition */

{

printf(" Nasa Mars mission successufull");

main();                               

}

---

• A Function is defined when Function name is followed by a pair of braces in which one or more statements may be present.

Example:

void India()                      /* Function Definition */

{

stmt 1;

stmt 2;

}

                                                                 That's All 

WAP to determine whether the Number is Prime or Not by using while and if Statement

Break Statement:

There are many situations where we want to jump out of a loop instantly. The keyword break allows us to do this. When break is encountered inside any loop, control automatically passes to the first statement after the loop. So Let us understand the break statement with the help of Program :-

Statement of C Program: This Program accepts a number and determined whether the number is Prime or not.

Prime Number:

A Prime number is one, which is divisible by 1 or itself.  Ex: 3 , 5 , 7 , 11 , 13 , 17 , 23 , 19 etc.

#include<stdio.h>

#include<conio.h>

void main()

{

int a , b ;

clrscr();

printf(" Enter the value of a\n");

scanf("%d" , &a);

b = 2;

while( b <= a-1 )

{

if(a % b == 0)

{

printf(" Entered Number is not Prime\n");

break;

}

b = b + 1;                                                   /*   b++     or    b += 1   */

}

if(b = a)

{

printf(" Prime Number\n");

}

getch();

}

Output1:

Enter the value of a

7

Prime Number

Output2:

Enter the value of a

9

Entered Number is not Prime

Explanation:

• In the above Program, if the condition { i.e a % b } turns out to be zero, then the message " Entered number is not Prime " is printed and after that the break statement encountered which causes control out of while loop.

• If the condition { i.e b == a } is true, then the message " Prime Number " is printed.

                                                                      

                                                                    That's All

WAP of C Language that calls many Functions

Statement of C Program : This Program prints the Messages or Instructions when different Functions calls: 

#include<stdio.h>

void England();                                      /* Function declaration */

void Australia();                                     /* Function declaration */

void India();                                           /* Function declaration */

int main()

{

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

England();                                                 /*  Function call */

Australia();                                                /*  Function call */

India();                                                      /* Function call */

return(0);

}

void England()                                             /* Function definition */

{

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

}

void Australia()                                             /* Function definition */

{

prinf(" I am in Australia\n");

}

void India()                                                   /* Function definition */

{

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

}

Output:

I am in main

I am in England

I am in Australia

I am in India

Note:  Number of Conclusions drawn from the above Program:

• A C Program is a collection of one or more Function or you can say A Function is a basic building block of C program.

• If a C program contain only one Function, then it must be main(), because Program execution always begins with main().

• In C program, as many number of Functions exist i.e there is no limit on the number of Functions.

• Control returns to main() after each Function has doing its work or thing.

• The Program ends, when main() runs out of statements and Function calls.

                                                               

                                                                 That's All

Write a Simple C Function Program that prints the Messages i.e Good Morning? & Good Evening!

Statement of C Program: This Program prints the Messages i.e Good Morning? & Good Evening! with the help of Function :

This is the Simplest C Function Program. Functions are the basic building blocks of C Program.

#include<stdio.h>

void msg();                                            /* Function Declaration */

int main()

{

msg();                                                         /* Function Call */

printf(" Good Morning?");

return(0);

}

void msg()                                               /* Function Definition */

{

printf(" Good Evening!");

}

 Output:

 Good Evening!

 Good Morning?

Explanation:

Above, we have defined two Functions- main() and msg(). We have used the word msg at three places in the Program. So Let us understood the meaning of each.

1. 

void msg();

This Function declaration indicates that msg() is a Function which after completing its execution does not return anything. The keyword void is used before the msg() to indicate that it 'does not return anything'.

2.

void msg()

{

printf(" Good Evening");

}

This is Function definition. In this definition we are using only printf(), but we can also use for , switch , if , while etc inside Function definition.

3. 

msg();

The Function msg() is being called by main() i.e main() calls the function msg(). We mean that control passes to the function msg().

                                                                       That's All

WAP to Find the Largest Number among Two Numbers by using Function

Statement of C Program: This Program prints the Largest Number among two Numbers by using Function.

#include<stdio.h>

#include<conio.h>

void main()

{

float a , b , max;

clrscr();

float large(float x , float y);                              /* Function declaration */

printf(" Enter the value of two numbers\n");

scanf("%f%f" , &a , &b);

printf("a = %f and b = %f\n" , a, b);

max = large(a,b);

printf(" The largest number is = %f\n" , max);

}                                                                   /* End of main() */

   /* Function to determine the largest number */

float large(float x , float y)

{

if(x>y)

{

return(x);

}

else                                                               /* ( y>x )  */

{

return(y);

}

}

Output:

 12.5

 10.5

 a = 12.5 and b = 10.5

 The largest number is = 12.5

                                                                     That's All

WAP to Compute the Sum of two Number by using Function

Statement of C Progream: This Program accepts two Integers and Computes their Sum via addnums() :
There are two methods to write this Program

1. NON ANSI style
2. ANSI style

1. NON ANSI style:

#include<stdio.h>
#include<conio.h>

void main()

{

int a , b , result;

clrscr();

printf(" Enter the value of two numbers\n");

scanf("%d%d" , &a , &b);

result = addnums(a , b);

printf(" sum of %d and %d = %d\n" , a , b , result);

}                                                      /* End of main */

/* Function to add two numbers */

int addnums( var1 , var2)

int var1 , var2;

{

int sum;

sum = var1 + var2;

return(sum);

}                                               /* End of Function */

Output:

Enter the value of two numbers

24

68

sum of 24 and 68 = 92

2. ANSI style:

#include<stdio.h>
#include<conio.h>

void main()

{

int a , b , result;

clrscr();

printf(" Enter the value of two numbers\n");

scanf("%d%d" , &a , &b);

result = addnums(a , b);

printf(" sum of %d and %d = %d\n" , a , b , result);

}                                                      /* End of main */

/* Function to add two numbers */

int addnums( int var1 , int var2)

{

int sum;

sum = var1 + var2;

return(sum);

}                                               /* End of Function */

Output:

Enter the value of two numbers

14

18

sum of 14 and 18 = 32

                                                                 That's All
                                                                   

Detailed overview of C Language Function [Tutorial]

Functions:
Function is a set of instructions to carry out a particular task. The Function after processing returns a single value.
In other word, we say a Function is a group of statements that can perform any particular task. 

Types of functions:

There are two types of Functions in C

1. Standard Functions  (Pre-defined Functions)


2. User-defined Functions

 1. Standard functions:

All standard functions, such as sqrt() , pow() , log() , sin() etc. are porvided in the library of the functions. The standard functions are also called library functions or built in functions. Predefined Functions are already created. Eg: printf() , scanf() , getch() , clrscr() etc.

2. User defined functions:

User defined Functions which are created by the User according to his need.

Function Defination:

Defining a function means writing an actual code for a function. Suppose you are defining a function which computes the square of a given number. Then you have to write a set of instructions to do this. There are different methods to define functions. The following two ways are used in defining functions:

1. NON ANSI style


2. ANSI style

1. NON ANSI style

The general form of NON ANSI function definition is as follows:

type name_of_the_function (parameter list)

parameter definition;

{

variable declaration;

stmt 1; 

stmt2;

.......

.......

return(value_computed);

}

where

• type => The data type of the return value by the function. 

• name_of_the_function => This is a user-defined function name.

• parameter list => List of variables that recieve, the value from the calling function. 

• parameter definition => Type declaration of the variables of the parameter list.

• return => A keyword used to send the output of the function, back to the calling function. There may be one or more return statements. When return is e

WAP to Find the Average Male Height and Female Height in the Class

Statement of C Program: This Program Prints the Average Height of Male and Female :

#include<stdio.h>

#include<conio.h>

void main()

{

int mh[3] , fh[3] , i ;           /* mh stands for Male Height and fh stands for Female Height */

float mtot , ftot ;          /* mtot stands for Male total height and ftot stands for Female total Height */

float mavg , favg ;       /* mavg stands for Males Average Height and favg stands for Females Average Height */

clrscr();

mavg = 0;

favg = 0;

for(i=0 ; i<3 ; i++)

{

printf(" Enter height of male %d :" , i+1);

scanf("%d" , &mh[i] );

mtot = mh[i] + mtot;

}

mavg = mtot/3;

printf("\n");

for(i=0 ; i<3 ; i++)

{

printf(" Enter height of female %d :" , i+1);

scanf("%d" , &fh[i] );

ftot = ftot + fh[i];

}

favg = ftot/3;

printf("\n");

printf(" Average of male height = %f\n" , mavg);

printf(" Average of female height = %f\n" , favg);

getch();

}                                                 /* End of main() */

 Output:

 Enter height of male 1 : 150

 Enter height of male 2 : 170

 Enter height of male 3 : 190

 Enter  height of female 1 : 160

 Enter  height of female 2 : 180

 Enter  height of female 3 : 200

 Average of male height = 170

 Average of female height = 180 

                                                                  
                                                                That's All

WAP to Find the Largest and Second Largest Number out of 10 Array Elements

Statement of C Program: This Program Prints the Largest and Second Largest Number out of 10 Array Elements:

#include<stdio.h>
#include<conio.h>
void main()
{
int A[10];
int i , j , b;
clrscr();

for(i=0 ; i<10 ; i++)
{
printf(" Enter the Number %d :" , i+1 );
scanf("%d" , &A[i] );
}

for(i=0 ; i<10 ; i++)
{
for(j=i ; j<10 ; j++)
{
if(A[i] < A[j])
{
b = A[j] ;
A[j] = A[i] ;
A[i] = b ;
}
}
}

printf(" Largest Number is : %d\n" , A[0] );
printf(" Second Largest Number is : %d\n" , A[1] );
getch();
}                                                     /* End of main() */

Output:

Enter the Number 1 : 90

Enter the Number 2 : 80

Enter the Number 3 : 70

Enter the Number 4 : 60

Enter the Number 5 : 50

Enter the Number 6 : 40

Enter the Number 7 : 30

Enter the Number 8 : 20

Enter the Number 9 : 10

Enter the Number 10 : 110

Largest Number is : 110

Second Largest Number is : 90

                                                                     That's All

Write a C Program to Find the Sum of All the Positive and Negative Numbers in Array

Statement of C Program: This Program reads N integers (+ve , -ve and zero) into an Array A and Finds

1. The sum of positive numbers
2. The sum of negative numbers
3. The average of all input numbers.

#include<stdio.h>

#include<conio.h>

#define MAX 8

void main()

{

int Array[MAX] ;

int i , N ;

int negsum , posum;    
/* negsum stands for Sum of Negative Numbers and posum stands for Sum of Positive Numbers */

float total , average;

clrscr();

negsum = 0 ;

posum = 0;

total = 0;

printf(" Enter the value of N\n");

scanf("%d" , &N);

printf(" Enter %d numbers( -ve , +ve and 0 )\n" , N);

for(i=0 ; i<N ; i++)

{

scanf(" %d" , &Array[i] );

}

printf(" Array elements\n");

for(i=0 ; i<N ; i++)

{

printf("%d\n" , Array[i] );

}

for(i=0 ; i<N ; i++)

{

if(Array[i] < 0)

{

negsum + = Array[i];

}

else if(Array[i] > 0)

{

posum + = Array[i] ;

}

else if(Array[i] == 0)

{

       ;

}

total + = Array[i];

}

average = total / N;

printf(" Sum of all positive numbers =%d\n" , posum);

printf(" Sum of all negative numbers =%d\n" , negsum);

printf(" Average of all input numbers %f\n" , average);

}                                                  / * End of main() */

 Output:

 Enter the value of N

  5

 Enter 5 numbers (-ve , +ve and 0)

  6

 -7

  0

 -3

  5

 Array elements

  6

 -7

  0

 -3

  5

 Sum of all positive numbers = +11

 Sum of all negative numbers = -10

 Average of all input numbers = 0.20

                                                                   That's All

Write a C Program to Calculate the Trace and Normal of a Matrix

Statement of C Program: This Program accepts a square matrix and prints the Trace and Normal of the Matrix.

Trace: Trace of a Matrix can be defined as the sum of the main diagonal elements.

 



Normal: Normal can be defined as the square root of the sum of squares of all the elements of a Matrix.

#include<stdio.h>

#include<conio.h>

void main()

{

int i , j , n ;                                       /* 'i' used for Rows and 'j' used for Columns */

int Row , Column;

int Matrix[9][9];

float trace , sum , normal;

clrscr();

trace = 0;

sum = 0;

printf(" Enter the order of Matrix\n");

scanf("%d * %d" , &Row , &Column);

printf(" Enter the elements of Matrix\n");

for(i=0 ; i<Row ; i++)

{

for(j=0 ; j<Column ; j++)

{

scanf("%d" , &Matrix[i][j] );

}

}

                                                  /* Trace and Normal */

for(i=0 ; i<Row ; i++)

{

for(j=0 ; j<Column ; j++)

{

if(i==j)

{

trace + = Matrix[i][j];                   /* It can also be Written as  trace=trace+Matrix[i][j]  */

}

sum + = pow( Matrix[i][j] , 2 );       

}

}

normal = sqrt(sum);

printf(" Trace = %f\n" , trace);

printf(" Normal = %f\n" , normal);
getch();

}                                                               /* End of main() */
 

Write a C Program to Print the Multiplication of Two Matrices

Statement of C Program: This Program accepts two Matrices of different or same order and Find the product of these Matrices and prints the Product Matrix:

Condition: The Column of First Matrix must be Equal to the Row of the Second Matrix.

#include<stdio.h>

#include<conio.h>

void main()

{

int Matrix A[9][9] , MatrixB[9][9] , Matrixsproduct [9][9] ;

int n , i , j , k;                              /* 'i' used for rows and 'j' used for columns */

int Row1 , Row2 , Column1 , Column2;

clrscr();

printf(" Enter the order of Matrix A\n");

scanf("%d * %d " , &Row1 , &Column1);

printf(" Enter the order of Matrix B\n");

scanf("%d * %d " , &Row2 , &Column2);

if(Column1 == Row2)

{

printf(" Enter the elements of Matrix A\n");

for(i=0 ; i<Row1 ; i++)

{

for(j=0 ; j<Column1 ; j++)

{

scanf("%d" , &Matrix A[i][j] );

}

}

printf(" Enter the elements of Matrix B\n");

for(i=0 ; i<Row2 ; i++)

{

for(j=0 ; j<Column2 ; j++)

{

scanf("%d" , &Matrix B[i][j] );

}

}

                                                     /* Product of two Matrices */

for(i=0 ; i<Row1 ; i++)

{

for(j=0 ; j<Column2 ; j++)

{

Matrixproduct[i][j] = 0 ;

for(k=0 ; k<Row2 ; k++)

{

Matrixproduct[i][j] = Matrixproduct[i][j] + ( Matrix A[i][k] * Matrix B[k][j] );

}

}

}

printf(" Product Matrix\n");

for(i=0 ; i< Row1 ; i++)

{

for(j=0 ;j< Column2;j++)

{

printf("%d" , Matrixproduct[i][j] );

}

printf("\n");

}

}                                                                    /* End of if */

else

{

printf(" Invalid order so Multiplication not possible\n");

}                                                                 /* End of main() */

 Output:

 Enter the order of Matrix A

 2 * 2

 Enter the order of MatrixB

 2 * 2

 Enter the elements of Matrix A

 1

 2

 3

 4

 Enter the elements of Matrix B 

 5

 6

 7

 8

 Product Matrix

 19      22

 43      50

                                                              That's All