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The import statement is used to bring certain classes and interfaces from other packages into our Java program, so we can access them without using their fully qualified names. We can use the short name instead. Java also supports static import statements, which were introduced in Java 5. It helps in accessing static members such as methods and constants. In this article, we are going to learn the difference between import and static import statements in Java. The import Statement in Java To access a class or method from another package, we need to either use the fully qualified ... Read More
A Type casting in Java is used to convert objects or variables from one data type to another. When we are converting or assigning one data type to another, automatic conversion will take place (if the types are compatible and the conversion is safe). However, if there is a risk of data loss, the conversion must be done explicitly by the programmer. Let's understand the types of Java type casting and the difference between them in this article. Types of Type Casting in Java Java Type Casting is classified into two types, which are: ... Read More
The NullPointerException is a subclass of the RuntimeException class. It is defined in java.lang package of Java. In this article, we are going to understand the reasons for NullPointerException and how to resolve them. Reason for NullPointerException in Java A NullPointerException is a runtime exception thrown by the JVM when our application code, another referenced API, or the middleware encounters the following conditions: Attempting to invoke an instance method of a null object. ... Read More
In Python, objects are instances of classes containing attributes and methods, while dictionaries are collections of key-value pairs. We can obtain a dictionary from an object's fields - Using __dict__ Using vars() Using __dict__ You can access an object's attributes as a dictionary using its _dict_ attribute. In Python, every object has a _dict_ attribute that stores the object's attributes and their values as a dictionary (key-value pairs). Example In this example, we have defined a class Company with attributes Companyname and Location, and created ... Read More
In Java, org.simple.json and org.json are two libraries that help in reading, writing, and manipulating JSON. But still, they are different. In this article, we are going to learn about these differences. Difference between JSON.simple vs JSON Let's see the below differences and they are - Features JSON.simple JSON ... Read More
In this article, we are going to learn how to replace the last occurrence of an expression in a string. In Python, String manipulation is a common task, and Python provides the built-in method named replace(). Though we can replace the specified character or substring in a string using this method, it does not directly support replacing the last occurrence. To achieve this we need to use slicing or a regular expression. Using Python rfind() Method The first approach is by using the Python rfind() method searches for the starting index of the last occurrence of the specified substring. Here, we ... Read More
A copy constructor is a type of constructor that uses another object from the same class that has been created previously, to initialize an object, whereas the assignment operator is used to assign a value to a variable. In this article, we will understand the difference between the copy constructor and the assignment operator in C++. Copy Constructor A copy constructor creates a new object by copying an existing object of the same class which has been created previously. It is of two types, i.e., Default and User-defined copy constructor. In the default copy constructor, ... Read More
The is a header file that includes all the standard C++ library. It is used during coding contests, as it helps in saving time while solving the problem since programmers do not have to remember all the header files. In the software engineering approach, we should reduce the use of this header file, as it includes lots of files, and sometimes that may not be required in the program. So it may increase the compile time. In this article, we are going to discuss why we should not use the header file ... Read More
In this article, we are going to learn about converting a string to binary, which means representing each character in the string using the binary digits 0 and 1. A binary number is a number expressed in the base2 numerical system, which uses only two symbols - 0 and 1. Since computers store data as binary, converting the strings into binary helps to understand how data is stored or transmitted. Python provides several methods to achieve this. Using Python ord() and format() Functions The first approach is by using the Python ord() and format(), Where the Python ord() ... Read More
Sorting the string that contains the number, such as ("xy1", "xy2", "xy10"), can be complex in Python. For example, if we sort the list ["xy1", "xy2", "xy10"] using the built-in sort() method, it results in ["xy1", "xy10", "xy2"]. But we will expect "xy2" to come before "xy10". It is because the Python default sorting uses the lexicographical order and compares the characters from left to right based on their Unicode values. Since the character '1' in "xy10" comes before "2" in "xy2", the "xy10" is treated as smaller, even though the number 10 is greater than 2. This ... Read More