Quick sort algorithm

http://btechsmartclass.com/data_structures/quick-sort.html

BFS: Breadth First Search of a Graph

http://btechsmartclass.com/data_structures/graph-traversal-bfs.html

What is JSP?

https://www.javaworld.com/article/3336161/what-is-jsp-introduction-to-javaserver-pages.html

How to run javascript inside a JSP scriplet

By writing your js code within <script></script> tag inside out.println() has shown below:

<%
    if( a > 9)
   {

         out.println("<script>document.getElementById('rd"+(a+1)+"').disabled=true;</script>");

   }

%>

How to comment JSP code

<%-- This is a JSP comment and will be completely ignored by the JSP compiler --%>

How to disable a option in a set of radio buttons

<input type="radio" name="disableme" id="1"> Animal
<input type="radio" name="disableme" id="2"> Mammal <input type="radio" name="disableme" id="3"> Human
document.getElementById("1").disabled = true;

source:

 https://www.w3schools.com/jsref/prop_radio_disabled.asp

https://stackoverflow.com/questions/13245672/how-to-disable-the-radio-button-using-javascript-not-using-any-js-framework

How to combine multiple jpg files into one PDF file

https://www.howtogeek.com/248462/how-to-combine-images-into-one-pdf-file-in-windows/

Subnet works - CIDR notation

https://en.wikipedia.org/wiki/Subnetwork

JDBC: Check if the record exists in the database

Assuming you are working with a newly returned ResultSet whose cursor is pointing before the first row, an easier way to check this is to just call isBeforeFirst(). This avoids having to back-track if the data is to be read.

if (!resultSet.isBeforeFirst() ) {   
    System.out.println("No data"); } else{ while(resultSet.next()){ resultSet.getString(1);       resultSet.getString(1); …. ….       resultSet.getString(n); } } source: https://stackoverflow.com/questions/867194/java-resultset-how-to-check-if-there-are-any-results

Java enums

Let us see another example of Java enum where we are using value(), valueOf(), and ordinal() methods of Java enum.

1. class EnumExample1{  
2. //defining enum within class  
3. public enum Season { WINTER, SPRING, SUMMER, FALL }  
4. //creating the main method  
5. public static void main(String[] args) {  
6. //printing all enum  
7. for (Season s : Season.values()){  
8. System.out.println(s);  
9. }  
10. System.out.println("Value of WINTER is: "+Season.valueOf("WINTER"));  
11. System.out.println("Index of WINTER is: "+Season.valueOf("WINTER").ordinal());  
12. System.out.println("Index of SUMMER is: "+Season.valueOf("SUMMER").ordinal());  
13.   
14. }}  

Output:

WINTER
SPRING
SUMMER
FALL
Value of WINTER is: WINTER
Index of WINTER is: 0
Index of SUMMER is: 2

source: https://www.javatpoint.com/enum-in-java