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| Core java - Interview Questions and Answers for 'Guidewire' - 3 question(s) found - Order By Newest | ||||
 Very frequently asked. Among first few questions in almost all interviews. Among Top 5 frequently asked questions. Frequently asked in Indian service companies (HCL,TCS,Infosys,Capgemini etc based on multiple feedback ) and Epam Systems | ||||
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| Ans. "equals" is the method of object class which is supposed to be overridden to check object equality, whereas "==" operator evaluate to see if the object handlers on the left and right are pointing to the same object in memory. x.equals(y) means the references x and y are holding objects that are equal. x==y means that the references x and y have same object. Sample code: String x = new String("str"); String y = new String("str"); System.out.println(x == y); // prints false System.out.println(x.equals(y)); // prints true | ||||
 Sample Code for equals | ||||
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 Discuss Correct / Improve  java string comparison string object class == equals object equality operator == vs equals equals vs ==  Asked in 294 Companies  basic  frequent | ||||
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 Related Questions | ||||
 What is the difference between = and == in Java ? | ||||
| How is == operator different for objects and primitive types ? | ||||
| What will be the output of following code Integer x = 1; Integer y = 2; System.out.println(x == y); What if you change 1 to "1" and Integer to String? | ||||
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| Ans. There are total six ways 1. literals When we create a String using double quotes, JVM looks in the String pool to find if any other String is stored with same value. If found, it just returns the reference to that String object else it creates a new String object with given value and stores it in the String pool. 2. new keyword When we use new operator, JVM creates the String object but dont store it into the String Pool. We can use intern() method to store the String object into String pool or return the reference if there is already a String with equal value present in the pool. 3. string buffer 4. string builder 5. System.out.println 6. char to string | ||||
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| Discuss Correct / Improve java string class string jvm memory management string pool Asked in 5 Companies basic frequent | ||||
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| Related Questions | ||||
| Does garbage collection guarantee that a program will not run out of memory? | ||||
| Describe, in general, how java's garbage collector works ? | ||||
| Describe what happens when an object is created in Java ? | ||||
| What are various types of Class loaders used by JVM ? | ||||
| Why two types of memory - stack and heap are required by Java ? | ||||
| Should we override finalize method ? | ||||
| What are strong, soft, weak and phantom references in Java ? | ||||
| Which memory areas does instance and static variables use ? | ||||
| Can we call the garbage collector explicitly ? | ||||
| Frequently asked in Infosys India | ||||
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| Ans. String pool (String intern pool) is a special storage area in Java heap. When a string is created and if the string already exists in the pool, the reference of the existing string will be returned, instead of creating a new object and returning its reference. | ||||
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| Discuss Correct / Improve java oops string string class string pool heap memory Asked in 31 Companies intermediate frequent | ||||
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| Related Questions | ||||
| Why Char array is preferred over String for storing password? | ||||
| What are different ways to create String Object? Explain. | ||||
| How does making string as immutable helps with securing information ? How does String Pool pose a security threat ? | ||||
| Which memory segment holds String Pool in Java ? | ||||
| How and Why Strings are interned in Java ? | ||||
| What will be the output of following code Integer x = 1; Integer y = 2; System.out.println(x == y); What if you change 1 to "1" and Integer to String? | ||||
| What will be result of following code and why Integer int1 = 1; Integer int2 = 1; String str1 = new String("str"); String str2 = new String("str"); String str3 = "str"; String str4 = "str"; System.out.println(int1 == int2); System.out.println(str1 == str2); System.out.println(str3 == str4); | ||||
| What is the purpose of String Pool ? Don't you think it's a performance overhead to have unnecessary check for string in string pool ? | ||||
| Why string pool concept has been introduced in string ? | ||||
