Java Basics - Lecture 2 - String concatenation in Java

In previous lecture we have covered Java, Eclipse, Data types and println(), print() methods. Now lets move forward on next topics

Lecture 2 Agenda

1. String Concatenation
2. If-else conditions

String Concatenation

- Addition of multiple strings is called string concatenation

- “+” sign is called concatenation operator

    

        int a = 100;

        int b = 200;

        String x = "Hello";

        String y = "World";

        System.out.println(a+b);

        System.out.println(x+y);

        System.out.println(a+b+x+y);

        System.out.println(x+y+a+b);

        System.out.println(x+y+(a+b));

        System.out.println(a+x+b+y);

Output:

       300

       HelloWorld

       300HelloWorld

       HellowWorld100200

       HelloWorld300

       100Hello200World

If-Else Conditions

- Are used to compare data

- Comparison operators <, >, <=, >=, ==,!=, &

       int a = 10;

       int b = 20;

       if(b>a) {

       

          System.out.println("b is greatest");

       }

       

       else {

       System.out.println("a is greatest");

     }

- b is greater than a, condition is true so if statement will be executed.

      if(b<a) {

      System.out.println("b is greatest");

     

     }

     else {

     System.out.println("a is greatest");

}

- b is greater than a, condition is false so else statement will be executed.

      

       int c = 40;

       int d = 50;

       

       if(c==d) {

       System.out.println("c and d are equal");

        

       }

       else {

       System.out.println("c and d are not equal");

   }

- Find a highest number

       int a = 100;

       int b = 200;

       int c = 300;

       if(a>b & a>c) {

       System.out.println("a is greatest");

       }

       else if(b>c) {

       System.out.println("b is greatest");

       }

       else {

       System.out.println("c is greatest");

}