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The class named File of the java.io package represents a file or directory (path names) in the system. This class provides various methods to perform various operations on files/directories.To get the list of all the existing files in a directory this class provides the files class provides list() (returns names) and ListFiles() (returns File objects) with different variants.The List() methodThis method returns a String array which contains the names of all the files and directories in the path represented by the current (File) object.Using this method, you can just print the names of the files and directories.ExampleThe following Java program ... Read More
Using plt.savefig("myImagePDF.pdf", format="pdf", bbox_inches="tight") method, we can save a figure in PDF format.StepsCreate a dictionary with Column 1 and Column 2 as the keys and Values are like i and i*i, where i is from 0 to 10, respectively.Create a data frame using pd.DataFrame(d), d created in step 1.Plot the data frame with ‘o’ and ‘rx’ style.To save the file in PDF format, use savefig() method where the image name is myImagePDF.pdf, format = ”pdf”.To show the image, use the plt.show() method.Exampleimport pandas as pd from matplotlib import pyplot as plt d = {'Column 1': [i for i in ... Read More
A PyTorch tensor is like numpy.ndarray. The difference between these two is that a tensor utilizes the GPUs to accelerate numeric computation. We convert a numpy.ndarray to a PyTorch tensor using the function torch.from_numpy(). And a tensor is converted to numpy.ndarray using the .numpy() method.StepsImport the required libraries. Here, the required libraries are torch and numpy.Create a numpy.ndarray or a PyTorch tensor.Convert the numpy.ndarray to a PyTorch tensor using torch.from_numpy() function or convert the PyTorch tensor to numpy.ndarray using the .numpy() method.Finally, print the converted tensor or numpy.ndarray.Example 1The following Python program converts a numpy.ndarray to a PyTorch tensor.# import ... Read More
NodeJS provides inbuilt library crypto to encrypt and decrypt data in NodeJS. We can use this library to encrypt data of any type. You can do the cryptographic operations on a string, buffer, and even a stream of data. The crypto also holds multiple crypto algorithms for encryption. Please check the official resources for the same. In this article, we will use the most popular AES (Advanced Encryption Standard) for encryption.Configuring 'crypto' dependencyIn your project, check if NodeJS is initialized or not. If not, use the following command to initialize NodeJS.>> npm init -yThe 'crypto' library is automatically added while ... Read More
In this tutorial, we will learn how to display the selected option in a dropdown list with JavaScript. What is a dropdown list? A dropdown list is a switchable menu that enables users to select one item from various options. A drop-down list is generated with the tag is most frequently used in forms to gather user input. After submitting the form, the name attribute must refer to the form's data. The DOM API functions getElementById() and querySelector() can be used to choose a element. The process use the querySelector() function to first select the "button" and "select" ... Read More
In C, ++ and -- operators are called increment and decrement operators. They are unary operators needing only one operand. Hence ++ as well as -- operator can appear before or after the operand with same effect. That means both i++ and ++i will be equivalent.i=5; i++; printf("%d", i);and i=5 ++i; printf("%d", i);both will make i=6.However, when increment expression is used along with assignment operator, then operator precedence will come into picture. i=5; j=i++;In this case, precedence of = is higher than postfix ++. So, value of i is assigned to i before incrementing i. Here j becomes 5 and i becomes 6.i=5; ... Read More
Anybody dealing with databases must comprehend the distinction between DDL and DML commands because it has an impact on how data is saved, accessed, and modified. A collection of commands called DDL are used to specify a database's structure. Database objects including tables, views, indexes, and constraints can be created, modified, and deleted using these commands. DDL statements specify how the data is arranged and accessed rather than altering the data that is stored in the database. DML, on the other hand, is a set of instructions used to work with the data that is kept in the ... Read More
Compiling a Java program is very easy after JDK installation. Following are the steps −Open a command prompt window and go to the directory where you saved the java program. Assume it's C:\.Type 'javac MyFirstJavaProgram.java' and press enter to compile your code. If there are no errors in your code, the command prompt will take you to the next line (Assumption: The path variable is set).The file is compiled and you can see MyFirstJavaProgram.class file generated in the same folder.
Following are the notable differences between Class (static) and instance variables. Instance variables Static (class) variables Instance variables are declared in a class, but outside a method, constructor or any block. Class variables also known as static variables are declared with the static keyword in a class, but outside a method, constructor or a block. Instance variables are created when an object is created with the use of the keyword 'new' and destroyed when the object is destroyed. Static variables are created when the program starts and destroyed when the program stops. ... Read More
In DBMS (Database Management Systems), constraints are guidelines or limitations imposed on database tables to maintain the integrity, correctness, and consistency of the data. Constraints can be used to enforce data linkages across tables, verify that data is unique, and stop the insertion of erroneous data. A database needs constraints to be reliable and of high quality. What are the Constraints of DBMS? In DBMS, constraints refer to limitations placed on data or data processes. This indicates that only a particular type of data may be entered into the database or that only a particular sort of operation can be ... Read More