JAVA STRING INTERVIEW QUESTIONS AND ANSWERS

Answer: Yes , String can be used in the switch case in Java. Example: public class StringSwitchCase{ public static void main(String args[] ) { String gift =”Apple Watch”; switch(gift ) { case “IPhone” : System.out.println(“gift is Iphone”); break; case “Car” : System.out.println(“Gift is car”); break; case “AppleWatch” : System.out.println(“Gift is apple watch”); break; default :

Answer: Yes, it is possible to compare two strings using == operator . If you compare two strings using == operator , it compares the reference or adress value, but don’t compare the actual content . If you use equals() method to compare two strings , then it will compare the actual content of two

Answer : The basic difference between StringBuffer and StringBuilder is Thread safety and Synchronization . StringBuffer is Synchronized and thread-safe due to which multiple threads can safely use it . While StringBuilder is not Synchronized and so not thread-safe . StringBuffer is slower due to synchronization overhead. Whereas StringBuilder is fast as it avoids locking

Answer: A String object is immutable means its value cannot be changed after creation , whereas StringBuffer object is mutable , which means it’s characters or length can be changed directly without creating new memory objects . String uses the String Constant Pool for memory allocation , whereas StringBuffer directly use Heap Memory for memory

You should avoid using the + operator for string concatenation inside loops because it triggers excessive memory consumption and quadratic O(n^2) time complexity. As Strings are immutable , they cannot be modified in place . Every single + operation copies the entire existing string into a brand-new memory location . Instead of using + in

Yes, Strings can be garbage collected in Java. The eligibility for garbage collection of Strings in Java completely depends on how they were created. If Strings are created dynamically at runtime such as using the new keyword , concatenating non-constant strings or reading data from a file , those strings occupy memory in heap memory

In Java, String Interning is a memory optimization technique which ensures all distinct string values share a single copy in a specific memory region called the String Constant Pool. The intern() method is used for interning in Java. When str.intern() method is called , the JVM performs the following tasks : Example : String s1=”Gift”;

Yes, In Java String is Thread-Safe. The main reason for thread-safety of String is immutability of String . Once String object is created , its character sequence and internal state cannot be modified or altered . Threads can only read from a String object but never write to it , so there is no risk

In Java == is a relational operator , whereas equals() is a method of String class. The == operator compares object references , whereas the .equals() method compares the actual text content present inside the string objects. The == operator can be used to compare primitive values like int or char, whereas equals() method cannot

String object of string class are stored in Heap memory, not in stack area. Let’s go deep into this topic. String object can be created in two ways i.e. 1. By using string literal 2. By using the ‘new’ keyword String literal is created by using a double quote. While creating a string using string