Programming Articles - Page 2733 of 3366

The getTime() method of the java.sql.Date class retrieves and returns the time from the current timestamp in milliseconds (long) from epoch time 1, 1970 00:00:00.000 GMT.//Retrieving the date Date date = rs.getDate("Dispatch_Date");The constructor of the java.sql.Timestamp class accepts a long variable representing the time in milliseconds from the epoch time and constructs the Timestamp object.//Creating a Timestamp object. Timestamp ts = new Timestamp(date.getTime()));Using these, you can convert a Date object to TimeStamp object in JDBC.Assume we have established connection with MySQL database and created a table named dispatch_data using statement object as:Assume we have established connection with MySQL database and ... Read More

The C++ interfaces are implemented using abstract classes and these abstract classes should not be confused with data abstraction which is a concept of keeping implementation details separate from associated data. A class is made abstract by declaring at least one of its functions as a pure virtual function. A pure virtual function is specified by placing "= 0" in its declaration as follows : class Box { public: // pure virtual function virtual double getVolume() = 0; private: ... Read More

In C++ we can pass arguments into a function in different ways. These different ways are −Call by ValueCall by ReferenceCall by AddressSometimes the call by address is referred to as call by reference, but they are different in C++. Incall by address, we use pointer variables to send the exact memory address, but in call by reference we pass the reference variable (alias of that variable). This feature is not present in C, there we have to pass the pointer to get that effect.In this section, we will see what are the advantages of call by reference over call ... Read More

To find the Current Working Directory (CWD) in C or C++ is like asking your program: "Hey, where am I right now?". Simply we can say that it is like a folder of your program which is present and used to operate in. We can use functions like getcwd() from unistd.h in C/C++ or filesystem::current_path() from C++17. Below are the list of the ways to achieve this. Using getcwd() in C/C++ Using filesystem in C++17 Using getcwd() Function in C/C++ In C/C++, we use the getcwd() function. This function gets ... Read More

In C++, direct memory access is possible using pointers. However, the improper use of pointers can lead to problems such as dangling pointers, null pointers, void pointers, and wild pointers. You must have to fix these problems properly for correct code compilation and execution. Let us learn how these problems occur and how you can fix them. Dangling Pointer A dangling pointer is a variable that points to invalid or freed memory, causing errors if accessed. It is like calling a disconnected phone number. When the local variable is not static, the pointer pointing to it becomes dangling. Syntax Following ... Read More

The getTime() method of the Timestamp class retrieves and returns the time from the current timestamp in milliseconds (long) from epoch time 1, 1970 00:00:00.000 GMT.Timestamp timestamp = rs.getTimestamp("DispatTimestamp"); long time = timestamp.getTime();The constructor of the java.sql.Date class accepts a long variable representing the time in milliseconds from the epoch time and constructs the date object.//Printing the date of dispatch System.out.println("Date of dispatch: "+new Date(time));Using these, you can convert a TimeStamp object to Date object in JDBC.Assume we have established connection with MySQL database and created a table named dispatch_data using statement object as://Creating a Statement object Statement stmt = ... Read More

The SQL Count() function returns the number of rows in a table. Using this you can get the number of rows in a table.select count(*) from TABLE_NAME;Suppose we have established a connection with MySQL and created a table in the database named mydatabase using Statement object as://Creating the Statement object Statement stmt = con.createStatement(); //Query to create a table String query = "CREATE TABLE Cricketers_Data( "    + "First_Name VARCHAR(255), "    + "Last_Name VARCHAR(255), "    + "Date_Of_Birth Date, "    + "Place_Of_Birth VARCHAR(255), "    + "Country VARCHAR(255))"; //Executing the query stmt.execute(query); System.out.println("Table created......");In to this table we ... Read More

AVL tree is a self-balancing Binary Search Tree where the difference between heights of left and right subtrees cannot be more than one for all nodesTree rotation is an operation that changes the structure without interfering with the order of the elements on an AVL tree. It moves one node up in the tree and one node down. It is used to change the shape of the tree, and to decrease its height by moving smaller subtrees down and larger subtrees up, resulting in improved performance of many tree operations. The direction of a rotation depends on the side which ... Read More

The (int)x is C-style typecasting, where static_cast(x) is used in C++. This static_cast() gives a compile-time checking facility, but the C-style casting does not support that. This static_cast() can be spotted anywhere inside a C++ code. And using this C++ cast, the intentions are conveyed much better. In C like cast, sometimes we can cast some type pointer to a point some other type data. Like one integer pointer can also point character type data, as they are quite similar, the only difference is character has 1-byte, integer has 4-bytes. In C++, the static_cast() is more strict than C-like casting. ... Read More

In C/C++, omitting the curly braces assumes that only the first statement is the block and this leads to quite a few issues during debugging, as code is pretty tough to read and comprehend. Curly braces help us prevent errors and confusion, which also helps with the flow of the program. Proper Use of Curly Braces In C++, we can omit the curly braces after if-else statements, or after any loop. If we do not use curly braces, then only one statement after the if-else or loop will be considered under that block. Syntax The following is the syntax: − ... Read More