JAVA Chapter 2

 

Short notes --

/__________ 1. Operators & Expressions _________
        // ___ Arthmetics operators ___
         //int a= 4;
         //int b = 6%a; // % = will always give remender
       // System.out.println(b);
        //___ Assignment operators ____
        //int num2 = 2; // += ka mtlb num2 joh 2 hai usme 3 jad do
        //num2 += 3 ;
        //System.out.println(num2 );
        // ____Comparision Operators ____
        //System.out.println(3==8); // Mtlb print krega aager true toh true warna false
        // ___ Logical Operators ___
        //System.out.println(64>5 && 64<2); // mtlb 64 is greater than 5
        // true and but 64 is less than 2 toh false hai toh false print hoga
        // ____ Bitwise Operators ___
// _________ 2 . Precedence & Associativity of Operators in java ___
        /* mtlb saaf se baat hai bc ke java hai isme bodmas nhi lgta isme hota hai operators jesa
        (+,-,/,*) isme rules hoga java ke phela kya hoga phela multiply hoga ya divide add hoga ya minus
         iss cheez ho pdta hai hmm Precedence  of operators in java mein*/
        //int a = 6*5-34/2
        /*
         >>>>>>>According to Precedence
          aab kyuki multiply ke prefeence jada hai toh
               = 30-34/2
               = 30 - 17
               = 13
         */
        //int b = 60/5-34*2
        /*
        >>>>>>>> According to Associativity
                              |||  abb isme multiply aur divide hai jinke precedence same hoti hai toh
              = 12 -34*2    |||  ham isme dekhe gye associatibity jiske according aager divide ya multiply
              = 12 - 28       |||  ho toh equation left to right solve hoti hain
              = -56
        */
        // Quick Quiz
        /* int x = 6;    // Precedence same hai toh associativity ke according left to right
        int y =2 ;
        int k = x*y/2;
        System.out.println(k); */

        /*int b = 2;
        int a = 4;       // Precedence same hai toh associativity ke according left to right
        int c = 3;
        int t = b*b - 4*a*c/2*c ;
        System.out.println(t); */

        /*int v = 2;
        int u = 4;      // Precedence  ke according phela multiply phir minus
        int k = v*v - u*u;
        System.out.println(k);*/

        /*int a = 2 ;
        int b = 4;      // Precedence  ke according phela multiply phir minus
        int d = 6 ;
        int k = a*b-d;
        System.out.println(k);*/

//_________ 3. Resulting Data Types After Arthmatics operations ___________
        /*
        Isme hame yesh dekhna hai ke aager hm do data types ko operate krte hai aur joh unke resultant
        aate hai evalution ke baad uske kya data type hoga
         */
        //int a = 653 + 33 ; // yeh aak int he aayega kyuki dono value int ke the
        //float b = 44.5f + 33 ; // float + int = int
        /*
        byte + short = int
        short + int = int
        charater + int = int
        character + short = int
        long + float = float
        int + float = float
        long + double = double
        float + double = double
         */
        // Increment and Decrement Operators
        // Increment ------->>>
       /* 1.  int i = 56;
           System.out.println(i++); // result aayega 56
           System.out.println(i);   // aab result aayega 57 KYU -- Kyuki i++ ka mtlb hai ke phela i ho print kro
                                // phir usme ++ mtlb aak bda do

        */

       /* 2. int j = 56;
             System.out.println(++j ); // ab result aayega 57 kyuki isme phela add hoga phir print
        */

        // Decrement ------->>>
       /* 1.  int i = 56;
           System.out.println(i--); // result aayega 56
           System.out.println(i);   // aab result aayega 55 KYU -- Kyuki i-- ka mtlb hai ke phela i ho print kro
                                // phir usme -- mtlb aak km kr  do

        */

       /* 2. int j = 56;
             System.out.println(--j ); // ab result aayega 55 kyuki isme phela minus hoga phir print
        */
        // Quick Quiz
        /* int y = 7;
         int x = ++y * 8 ;  // ++y = 8 the 8*8 = 64
        System.out.println(x); */

EXERCISE - 2

// Exercise 2 __________________________________
 //1. what will be the result of the following
        //float a = 7/4.0f * 9/2.0f ;      // Precedence  ke according mutlipy aur divide
        //System.out.println(a);   // same to associavity ke according left to right
     // jb tk 7/4 ke piche .0f ne lage gya toh yeh integre hoga iske value toh aayega 1.56 pr
     // kyuki integer hai toh java ko yeh 1 dikhe gye iske liya .0f

//2. Write a program to encrypt a grade by adding 8 to it decrpty it to show corrct value
       //Encrypt
            //char grade = 'B';
           //grade = (char)(grade + 8 );
           //System.out.println(grade);
        // Decrypt
           //grade = (char)(grade - 8 );
           //System.out.println(grade);

//3.Use comparison operators to find that the entered number is greater than the number exixting or not
        //Scanner sc  = new Scanner (System.in);
        //System.out.print("Enter your value you want to check = ");
        //int a = sc.nextInt();
        //System.out.println(a>3);

//4. write the expression
        /*int v = 2;
        int u= 3;      // phela multiply phir minus
        int a= 2 ;
        int s = 2 ;
        int t = v*v -u*u/2*a*s;
        System.out.println(t); */

//5. Find the value of the given expression

       // int a = 7*49/7+ 35/7; // divide bhi hai aur multipy bhi toh solve hoga from left to right
        //System.out.println(a);

Code with harry --