Core Java Interview Questions, Answers for Freshers and Experienced asked in various Company Job Interviews

Core Java Interview Questions

Questions Answers Views Company eMail

Implement two stacks using a single array.

Global Logic,

1109

What is the use of 'super' keyword inside a constructor?

Flextronics, Thomson Reuters, Virtusa,

1024

What is the method to declare member of a class static?

HCL,

1057

What is Mutex (Mutual Exclusion Object) ?

Ciena,

1217

Give differences between Quicksort &Mergesort. When should these sorts be used andwhat is their running time in java?

Genpact,

1290

What do you mean by JVM?

Ericsson,

1143

When does a class need a virtual destructor?

Flextronics,

1069

How is tree Mirroring implemented?

Fidelity,

1125

How can u increase the heap size in the memory?

Infosys,

1070

What do you understand by abstract classes?

HCL,

1138

How do you implement tree mirroring in java?

EXL, HCL,

1126

Explain the key functions of data binding?

Akamai Technologies, Aspire, Impetus, Infogain, Tavant Technologies, Virtusa,

1070

What is Major and importance difference between for and foreach loop ?

Infosys,

1209

What is the use of generics? When was it added to the Java development Kit?

Impetus,

1068

Explain the difference between a Thread and a Process.

Ciena,

1050

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Un-Answered Questions { Core Java }

What do you understand by java virtual machine?

1241

What is difference between module and function?

1263

What is use of arraylist in java?

1243

what do you mean by marker interface in java?

1024

What is casting in java programming?

1089

Can sleep() method causes another thread to sleep?

1080

What is the difference between form & report?

1092

What is purpose of applet programming?

1242

What is the Concept of Encapsulation in OOPS

1035

What is try-with-resources in java?

1225

Is node a data type in java?

1062

How does finally block differ from finalize() method?

1110

What are the 5 types of research methods?

1196

how a programmer confirms that the data submitted has been succesfully inserted into the database(either oracle or my sql).. How a programmer confirm if there is any problem with the program he wrote for insertion... ANS:--- >executeupdate method is having boolean return type, if anything goes wrong in data insertion or data updation, it would return false. otherwise, if it successfully inserts data into the database, it would return true NOW HOW TO I CHECK IN MY DURING EXECUTION WHETHER IT RETURNS TRUE OR FALSE... WELL IT WILL DISPLAY ANY MESSAGE OR NOT

2486

Explain about transient variables in java?

1151

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