programming languages Online Quiz - 68

String literals in C are stored in read-only memory. Attempting to modify them through a pointer (like *name='X') causes undefined behavior and typically results in a segmentation fault. The correct approach is to use a character array (char name[] = "David") if you need to modify the string contents.

The expression i++ * ++i modifies the variable i twice without an intervening sequence point, which is undefined behavior in C (before C11) and C++. The compiler is free to evaluate these operations in any order, leading to unpredictable results. Such expressions should always be avoided in production code.

In C (but not C++), casting the return value of malloc is unnecessary because void* automatically converts to any pointer type. In fact, explicit casting can hide errors if you forget to include stdlib.h. The cast is only necessary in C++ or when compiling C code with a C++ compiler.

The GenericServlet class implements Servlet and provides getServletConfig() to retrieve the ServletConfig object passed to the init(ServletConfig) method. getServletInfo() returns descriptive text, and getInitParameters() does not exist directly with that name on GenericServlet.

In JSP, the session implicit object is unavailable if the page directive disables sessions (session="false"). The exception implicit object is only available on error pages (isErrorPage="true"). Thus, under standard configurations, both may be unavailable depending on the directives configured.

In Entity JavaBeans (EJB), the ejbCreate() method for Container-Managed Persistence (CMP) beans returns null. For BMP (Bean-Managed Persistence) beans, it returns the primary key class. This is a key difference between CMP and BMP bean creation methods.

In Java, an abstract method declaration must not have a method body (no braces {}) and must end with a semicolon, preceded by the abstract keyword. Therefore, abstract double area(); is the correct syntax. Option 607836 lacks a semicolon, and the others include braces.

The code uses assignment (=) instead of equality (==). In Java, var = true assigns true to var and returns true, so the condition is true and 'TRUE' is printed. This is a common mistake that compiles and runs but produces unexpected behavior.

An infinite loop is a loop that executes indefinitely without terminating. Option B correctly defines this. Option A describes a well-functioning loop (not necessarily infinite). Option C describes a loop that never starts (not infinite). Option D describes a non-functional loop (different concept).

JDBC 2.0 introduced scrollable result sets, which allow developers to move the cursor both forward and backward, as well as relative to its current position or to an absolute position.

The ServletConfig interface is used by the servlet container to pass initialization parameters and configuration information to a servlet instance during its initialization (via the init method). WebXML is not a standard interface, and Structs Config is a framework-specific concept.

Class.forName() dynamically loads a driver class and registers it with the DriverManager. This is the standard JDBC pattern for driver loading. When a driver class is loaded, its static initializer registers the driver with DriverManager, making it available for connections.

In Struts Action classes, doPost() handles POST requests and doPost() is indeed used for posting information. doGet() handles GET requests. execute() is the older Struts 1.x method, and validate() is for input validation, not posting data.

In Java's I/O library, java.io.Writer is the abstract superclass for all character-oriented output streams. Classes like FileWriter inherit from it. OutputStream and FileOutputStream are for byte streams, not character writing, and CharWriter is not a standard JDK class.

Constructors are special methods invoked automatically when a new object is instantiated using the 'new' keyword. They initialize the object's state and set up required resources. Methods must be called explicitly, garbage collection runs automatically to reclaim memory, and finalizers are called before garbage collection (not during object creation).

Java requires the source filename to match the public class name. If a file contains 'public class Test', it must be named Test.java for successful compilation. Package statements are optional, java.lang is auto-imported, and the class must already be declared (that's not a separate requirement).

Cookies are small text files stored on the client side that maintain state information across HTTP requests. Sessions are server-side mechanisms (cookies often store the session ID). HttpRequest/HttpResponse are request/response objects, not state storage. Java Beans are component models, not state mechanisms.

Modern web and application servers support dynamic class reloading or hot deployment, meaning a servlet class can be recompiled and reloaded without shutting down the entire web server. This makes the statement false, making the designated 'False' option correct.

Data types define the kind of values a variable can hold (int, void for return type, Button as a class type). 'public' is an access modifier keyword that controls visibility, not a data type. Access modifiers and data types are different categories in Java.