How many objects would be created in the following code string s1 hello string s2 Hello?
What is a Java String? In Java, a string is an object that represents a sequence of characters or char values. The java.lang.String class is used to create a Java string object. Show
There are two ways to create a String object:
Now, let us understand the concept of Java String pool. Java String Pool: Java String pool refers to collection of Strings which are stored in heap memory. In this, whenever a new object is created, String pool first checks whether the object is already present in the pool or not. If it is present, then same reference is returned to the variable else new object will be created in the String pool and the respective reference will be returned. Refer to the diagrammatic representation for better understanding: In the above image, two Strings are created using literal i.e “Apple” and “Mango”. Now, when third String is created with the value “Apple”, instead of creating a new object, the already present object reference is returned. That’s the reason Java String pool came into the picture. Before we go ahead, One key point I would like to add that unlike other data types in Java, Strings are immutable. By immutable, we mean that Strings are constant, their values cannot be changed after they are created. Because String objects are immutable, they can be shared. For example:
String str =”abc”; char data[] = {‘a’, ‘b’, ‘c’}; Let us now look at some of the inbuilt methods in String class. Get Certified With Industry Level Projects & Fast Track Your Career Java String Methods
public class Example{ public static void main(String args[]{ String s1="hello"; String s2="whatsup"; System.out.println("string length is: "+s1.length()); System.out.println("string length is: "+s2.length()); }} Here, String length() function will return the length 5 for s1 and 7 for s2 respectively.
public class CompareToExample{ public static void main(String args[]){ String s1="hello"; String s2="hello"; String s3="hemlo"; String s4="flag"; System.out.println(s1.compareTo(s2)); // 0 because both are equal System.out.println(s1.compareTo(s3)); //-1 because "l" is only one time lower than "m" System.out.println(s1.compareTo(s4)); // 2 because "h" is 2 times greater than "f" }} This program shows the comparison between the various string. It is noticed that
Let’s understand this with a programmatic example: public class StringValueOfExample{ public static void main(String args[]){ int value=20; String s1=String.valueOf(value); System.out.println(s1+17); //concatenating string with 10 }} In the above code, it concatenates the Java String and gives the output – 2017.
public class IsEmptyExample{ public static void main(String args[]) { String s1=""; String s2="hello"; System.out.prinltn(s1.isEmpty()); // returns true System.out.prinltn(s2.isEmpty()); // returns false }} In the above code, the first print statement will return true as it does not contain anything while the second print statement will return false.
public class EndsWithExample{ public static void main(String args[]) { String s1="hello how are you”; System.out.println(s1.endsWith("u")); // returns true System.out.println(s1.endsWith("you")); // returns true System.out.println(s1.endsWith("how")); // returns false }} This is not the end. There are more Java String methods that will help you make your code simpler. Moving on, Java String class implements three interfaces, namely – Serializable, Comparable and CharSequence. Since, Java String is immutable and final, so a new String is created whenever we do String manipulation. As String manipulations
are resource consuming, Java provides two utility classes: StringBuffer and StringBuilder.
I hope you guys are clear with Java String, how they are created, their different methods and interfaces. I would recommend you to try all the Java String examples. Do read my next blog on Java Interview Questions which will help you set apart in the interview process. Now that you have understood basics of Java, check out the Java Certification training by Edureka, a trusted online learning company with a network of more than 250,000 satisfied learners spread across the globe. Edureka’s Java J2EE and SOA training and certification course is designed for students and professionals who want to be a Java Developer. The course is designed to give you a head start into Java programming and train you for both core and advanced Java concepts along with various Java frameworks like Hibernate & Spring. Got a question for us? Please mention it in the comments section of this “Java String” blog and we will get back to you as soon as possible or you can also join Java Training in Amritsar. How many objects will be created String s new String Hello?The answer is: 2 String objects are created.
How many objects will be created in the following code 1 String s1 Welcome 2 String s2 welcome 3 String s3 welcome?89)How many objects will be created in the following code? String s = new String("Welcome"); Answer is : Two objects, one in string constant pool and other in non-pool(heap). You have both question and answer.
How many objects are created in the following code String s1 new String ABC String s2 new String ABC String s3 ABC?Correct Answer: C
In statement 1, “abc” is created in the String pool. In statement 2, first of all “abcd” is created in the string pool. Then it's passed as an argument to the String new operator and another string gets created in the heap memory. So a total of 3 string objects gets created.
How many objects would be created in the following code?The commonly agreed answer to this interview question is that two objects are created by the code.
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