Core Java - Interview Questions and Answers for 'Builder' - 10 question(s) found - Order By Newest Very frequently asked in different variations. Frequently asked in Deloitte ( 2 feedback ) , HCL Tech ( 3 feedback ), TCS and Coginizant (CTS) Q1. Explain the scenerios to choose between String , StringBuilder and StringBuffer ?
or
What is the difference between String , StringBuilder and StringBuffer ? Core Java
Ans. If the Object value will not change, use String Class because a String object is immutable.
If the Object value can change and will only be modified from a single thread, use StringBuilder because StringBuilder is unsynchronized(means faster).
If the Object value may change, and can be modified by multiple threads, use a StringBuffer because StringBuffer is thread safe(synchronized). Sample Code for String Sample Code for StringBuffer Sample Code for StringBuilder Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  java   string class   string   stringbuilder   stringbuffer   String vs StringBuffer   String vs StringBuilder   String vs StringBuilder vs StringBuffer   StringBuffer vs stringBuilder Asked in 29 Companies basic   frequent Try 3 Question(s) TestVery frequently asked. Usually difference between String,StringBuffer and StringBuilder is asked in different variations. Q2. Difference between StringBuffer and StringBuilder ? Core Java
Ans. StringBuffer is synchronized whereas StringBuilder is not. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  java   string   stringbuffer   string class   stringbuilder   synchronized   basic interview question   infosys technologies Asked in 17 Companies basic   frequent Try 1 Question(s) Test Q3. Difference between Factory and Builder Design Pattern ? Design
Ans. Builder pattern is the extension of Factory pattern wherein the Builder class builds a complex object in multiple steps. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  java   design pattern   factory design pattern   builder design pattern Asked in 1 Companies expert Q4. Difference between Builder and Composite ?
Ans. Builder is a creational Design Pattern whereas Composite is a structural design pattern. Composite creates Parent - Child relations between your objects while Builder is used to create group of objects of predefined types. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  java   design pattern   builder   composite   creational design pattern   structural design pattern Q5. Write a method to check if input String is Palindrome? Core Java
Ans. private static boolean isPalindrome(String str) {
if (str == null)
return false;
StringBuilder strBuilder = new StringBuilder(str);
strBuilder.reverse();
return strBuilder.toString().equals(str);
} Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  java   string   stringbuilder   stringbuilder   string class   code   palindrome Asked in 38 Companies Basic   frequent Q6. Give an Example for Builder Pattern ? Core Java
Ans. String str = new StringBuilder().append("Buggy").append("Bread").toString(); Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  java   builder pattern   design pattern   stringbuilder   string Asked in 3 Companies Try 1 Question(s) Test Q7. Write code for the usage of Builder Design Pattern
Ans. http://javasearch.buggybread.com/CodeSnippets/searchCodeSamples.php?&category=code&searchOption&keyword=964 Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  builder design pattern  builder pattern  code  coding intermediate Q8. Write a class explaining builder pattern ? Design
Ans. public class BuggyBread {
private String element1 ;
private String element2 ;
private BuggyBread ( String element1 , String element2 ){
this . element1 = element1 ;
this . element2 = element2 ;
}
public static class Builder {
private String element1 ;
private String element2 ;
Builder ( BuggyBread buggybread ){
element1 = buggybread . element1 ;
element2 = buggybread . element2 ;
}
Builder withElement1 ( String element1 ){
this . element1 = element1 ;
return this ;
}
Builder withElement2 ( String element2 ){
this . element2 = element2 ;
return this ;
}
BuggyBread build (){
BuggyBread buggybread = new BuggyBread ( element1 , element2 );
return buggybread ;
}
}
}
Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  builder pattern  builder class Try 1 Question(s) Test Q9. Can StringBuffer and StringBuilder in Java be inherited? Core Java
Ans. No, they have been declared final and hence cannot be extended. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  StringBuffer  StringBuilder Q10. Do we have a method to reverse a string in String class ? Core Java
Ans. No but we have it in StringBuilder. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  String  StringBuilder  Reverse a string Q11. With the following code, Which is a valid way to initialize ?
public class BuggyBread {
private String element1;
private String element2;
private BuggyBread(String element1, String element2){
this.element1 = element1;
this.element2 = element2;
}
public static class Builder {
private String element1;
private String element2;
Builder(BuggyBread buggybread){
element1 = buggybread.element1;
element2 = buggybread.element2;
}
Builder withElement1(String element1){
this.element1 = element1;
return this;
}
Builder withElement2(String element2){
this.element2 = element2;
return this;
}
BuggyBread build(){
BuggyBread buggybread = new BuggyBread(element1,element2);
return buggybread;
}
}
} Core Java
a. BuggyBread buggybread = new BuggyBread(); b. BuggyBread buggybread = new BuggyBread("element1","element2"); c. BuggyBread.Builder builder = new BuggyBread.Builder(); d. BuggyBread.Builder builder = new BuggyBread.Builder("element1","element2");Ans.d. BuggyBread.Builder builder = new BuggyBread.Builder("element1","element2");
a. String b. StringBuffer c. StringBuilder d. None of these create immutable objects.Ans.a. String
a. String b. StringBuffer c. StringBuilder d. None of theseAns.b. StringBuffer
Q14. Which of the following class cannot be extended or inherited ?
StringBuffer , StringBuilder Core Java
a. StringBuffer b. StringBuilder c. Both cannot be extended d. Both can be extendedAns.c. Both cannot be extended