Reason for Data Insecurity

Reason for Data Insecurity

• It is the  GLOBAL VARIABLES which leads to the data insecurity in c- programs 
• GLOBAL VARIABLES would be available for both related and unrelated functions also.
• Whenever an unrelated function accesses the data in a wrong way data corruption arises

Sample c -program  

#include <stdio.h>
 
/* global variable declaration */
int a = 20;
 
int main ()
{
  /* local variable declaration in main function */
  int a = 10;
  int b = 20;
  int c = 0; 

int mul=0;

  c = sum( a, b);
  printf ("a+b = %d\n",  c); 

 mul= sum( a, b);
  printf ("a*b= %d\n",  mul);  

 return 0;
}

/* function to add two integers */
int sum(int a, int b)
{
    

    return a + b;
}

/* function to multiply two integers */
int mul(int a, int b)
{


    return a * b;
} 

Java program:

 package com.instanceofjavaforus;

public class Student {
  
// variables
    int rno;
    String name;
    String clas;

  
//setter and getter methods of variables  
    public int getRno() {
        return rno;
    }

    public void setRno(int rno) {
        this.rno = rno;
    }
    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getClas() {
        return clas;
    }

    public void setClas(String clas) {
        this.clas = clas;
    }

  
    //constructor
    Student(int rno,String name,String clas){
        this.rno=rno;
        this.name=name;
        this.clas=clas;
          }
  
    public static void main(String args[]){
      
        Student student= new Student(1, "sai", "class IV", "hyderabad", 1);
      
        System.out.println("Name: "+student.getName());
        System.out.println("Class: "+student.getClas());
        System.out.println("Rno: "+student.getRno());
       }
}