{"id":1214,"date":"2021-10-23T17:24:35","date_gmt":"2021-10-23T17:24:35","guid":{"rendered":"https:\/\/rahulshettyacademy.com\/blog\/?p=1214"},"modified":"2021-11-30T18:39:08","modified_gmt":"2021-11-30T18:39:08","slug":"sdet-interview-questions-part-1","status":"publish","type":"post","link":"https:\/\/rahulshettyacademy.com\/blog\/index.php\/2021\/10\/23\/sdet-interview-questions-part-1\/","title":{"rendered":"Sr.QA and SDET Interview Questions in Java – Part 1"},"content":{"rendered":"

This<\/a> is Part 1 in the series of SDET Interview questions and answers in Java<\/h3>\n

1. What is the difference between JDK, JRE, and JVM?<\/a><\/h3>\n

JDK<\/strong> is Java Development Kit it is used for Developing Java Application<\/p>\n

JRE<\/strong> is Java Runtime Environment that is used for running java programs\/application<\/p>\n

JVM<\/strong> is Java Virtual Machine that provides a Platform Independent execution environment for running your code.<\/p>\n

2. What are the different types of constructors in Java? And How to overload Constructor?<\/a><\/h3>\n

Constructor<\/strong> is a block of code, which will have a name as the Class name. The constructor will be executed when a new instance of the class is created.<\/p>\n

There are two types of Constructor<\/strong><\/p>\n

Default Constructor<\/strong><\/em><\/p>\n

Default constructor will not have any parameter, If you don\u2019t define it then compiles creates one automatically. Default constructor will be called by compiler if there is no other constructor.<\/p>\n

Example Code Snippet<\/span><\/span><\/p>\n

class Academy {<\/span><\/p>\n

    \/\/ Constructor<\/span><\/p>\n

    Academy() {<\/span><\/p>\n

          System.out.println(“Constructor called”);<\/span><\/p>\n

    }<\/span><\/p>\n

}<\/span><\/p>\n

public class SampleClass {<\/span><\/p>\n

    public static void main(String args[]) {<\/span><\/p>\n

            \/\/ this invokes default constructor.<\/span><\/p>\n

          Academy academy = new Academy();<\/span><\/p>\n

}  <\/span><\/p>\n

}<\/span><\/p>\n

           <\/span><\/p>\n

Output:<\/span><\/span><\/strong><\/p>\n

Constructor called<\/span><\/p>\n

Parameterized Constructor<\/strong><\/p>\n

The parameterized constructor will have parameters, this is mainly used for initialization purposes. You can pass different values to a parameterized constructor at the time of object creation, but values should match the constructor signature<\/p>\n

Example Code Snippet<\/span><\/p>\n

    class Academy {<\/span><\/p>\n

    int a=0;<\/span><\/p>\n

    int b=0;<\/span><\/p>\n

    \/\/ Parameterized Constructor<\/span><\/p>\n

    Academy(int a, int b) {<\/span><\/p>\n

          System.out.println(“Constructor called”);<\/span><\/p>\n

          System.out.println(“Addition of “+a+” and “+b+” = “+(a+b));<\/span><\/p>\n

    }<\/span><\/p>\n

}<\/span><\/p>\n

public class SampleClass {<\/span><\/p>\n

          public static void main(String args[]) {<\/span><\/p>\n

                      \/\/ this invokes default constructor.<\/span><\/p>\n

                Academy academy = new Academy(10,20);<\/span><\/p>\n

          }<\/span><\/p>\n

}<\/span><\/p>\n

Output:<\/span><\/strong><\/span><\/p>\n

Constructor called<\/span><\/p>\n

Addition of 10 and 20 = 30<\/span><\/p>\n

3. What is the static keyword? How it can be used?<\/a><\/h3>\n

The static indicates that the particular member belongs to a type itself, rather than to an instance of that type. That means a static member of the class can be accessed before creating any object for that class.<\/p>\n

Static keywords can be used for<\/p>\n