Pass 1z0-829 Exam Guide

The code fragment is creating a string variable “a” with the value “Hello! Java”. Then, it is printing the index of “Java” in “a”. Next, it is replacing “Hello!” with “Welcome!” in “a”. Then, it is printing the index of “Java” in “a”. Finally, it is creating a new StringBuilder object “b” with the value of “a” and printing the index of “Java” in “b”. The output will be 8109 because the index of “Java” in “a” is 8, the index of “Java” in “a” after replacing “Hello!” with “Welcome!” is 10, and the index of “Java” in “b” is 9. References: Oracle Java SE 17 Developer source and documents: [String (Java SE 17 & JDK 17)], [StringBuilder (Java SE 17 & JDK 17)]

The code fragment is using the switch statement with the new Java 17 syntax. The switch statement checks the value of the variable rank and executes the corresponding case statement. In this case, the value of rank is 4, so the first case statement is executed, printing “Range1”. The second and third case statements are also executed, printing “Range2” and “Range3”. The default case statement is also executed, printing “Not a valid rank”. References: Java Language Changes - Oracle Help Center

The code will not compile because the variable ‘x’ is declared as final and then it is being modified in the switch statement. This is not allowed in Java. A final variable is a variable whose value cannot be changed once it is initialized1. The switch statement tries to assign different values to ‘x’ depending on the value of ‘y’, which violates the final modifier. The compiler will report an error: The final local variable x cannot be assigned. It must be blank and not using a compound assignment. References: The final Keyword (The Java™ Tutorials > Learning the Java Language > Classes and Objects)