Programming Articles - Page 1982 of 3363

How to implement String utility and immutability in JShell in Java 9?

raja
Updated on 27-Apr-2020 18:01:09

145 Views

JShell is an interactive command-line tool used to implement simple statements like expressions, classes, methods, fields, interfaces, and etc. String class is part of the built-in java.lang package and provides several methods for common text processing.1) String Utility: String provides several built-in utility methods. The methods like indexOf(), lastIndexOf(), startsWith(), endsWith(), isEmpty(), equals(), equalsIgnoreCase() are that part of string utility.In the below code snippet, we have implemented the string utility methods in the JShell tool.Snippet-1jshell> String str = "JShell is a new feature in Java9"; str ==> "JShell is a new feature in Java9" jshell> str.indexOf("new") $4 ==> 12 ... Read More

What are the rules we need to follow in JShell in Java 9?

raja
Updated on 27-Apr-2020 12:18:03

250 Views

Java 9 introduced an interactive REPL (Read-Evaluate-Print-Loop) tool: JShell, and it allows us to execute code snippets and get an immediate result. A snippet is an instruction that can use standard Java syntax. It represents a single expression, statement, or declaration.Below are some of the rules we need to follow while using the JShell tool.Rules for JShell tool:A snippet is like import declarations, class declarations, method declarations, interface declarations, field declarations, statements, and primary expressions.The package declarations are not allowed. JShell code is placed under the transient JShell package.The access modifiers: public, protected, and private, and the modifiers: final and static are not allowed in ... Read More

What is the use of the "requires" clause in a module-info file in Java 9?

raja
Updated on 28-Apr-2020 13:21:42

2K+ Views

A module is an important concept introduced in Java 9. By using this concept, we can able to divide code into smaller components called modules. Therefore, each module has its own responsibility and declare its dependency on other modules to work properly. In order to declare a module, we need to include the "module-info.java" file to root source code.There are few types of "requires" clause in "module-info" file1)  requires : By default, a module doesn't know other modules present in a module-path. So, it is necessary to add a line in our module-info.java: "requires" each time when we want to access ... Read More

How to declare reference types in JShell in Java 9?

raja
Updated on 24-Apr-2020 19:46:37

222 Views

JShell is an interactive tool in Java 9 that allows user inputs, evaluates it, and prints output to the user.Unlike a value type, a reference type doesn't store its value directly. Instead, it will store the address where a value is stored. It means that a reference type contains a pointer to another memory location that holds the data. The reference types are String, arrays, class, and delegates.In the below code snippet, when we create a new instance of Animal, it can be created on the heap memory. The new Animal() creates an object on the Heap. Animal@73846619, the object is ... Read More

What is the use of the jdeprscan tool in Java 9?

raja
Updated on 24-Apr-2020 17:33:05

320 Views

The jdeprscan tool can be used for static analysis of classes, archives, and folders for the presence of API elements marked as deprecated. This tool only detects items marked as deprecated in Java SE, and it doesn't detect marked items in other libraries. All classes on which the examined class or set of classes depends must be available when compiling or running a class. In the absence of a dependent class, this tool provides a list of unavailable classes preceded by the error: cannot find a class.Below is the syntax for the jdeprscan tool.Syntaxjdeprscan [options] {dir | jar | class}The "jdeprscan" command can be supported by "jmods\jdk.jdeps.jmod" ... Read More

How to initialize an array in JShell in Java 9?

raja
Updated on 24-Apr-2020 16:43:30

524 Views

JShell is a command-line tool used to evaluate simple statements, expressions, classes, methods, variables, etc.. and prints the output immediately to the user.An array in Java is also an object. We need to declare an array and then created. In order to declare a variable that holds an array of integers, we can mention like int[] array. In an array, the index starts from 0 to (length of array - 1).In the below code snippet, we can use an index to find the specific element from the array. It will be done by using an indexing operator: []. The expression marks[0] maps ... Read More

How to create wrapper objects in JShell in Java 9?

raja
Updated on 24-Apr-2020 14:18:37

309 Views

Each primitive type in Java has a corresponding built-in wrapper class, and these wrapper classes are also immutable. Integer, Float, Double, Byte, and etc.. are some of the built-in wrapper classes. The main incentive of using such wrappers in our code is accessing type information about the corresponding primitive type, Auto-Boxing feature, where a primitive data is automatically promoted to an object reference type, and moving primitive type data around data structures.We can create an instance of Wrapper Classes by using a new operator, and also use the valueOf() method within types such as Integer to create a wrapper object. ... Read More

Calculating Wind Chill Factor(WCF) or Wind Chill Index(WCI) in Python Program

Hafeezul Kareem
Updated on 24-Apr-2020 12:40:14

543 Views

In this tutorial, we are going to learn how to calculate Wind Chill Index in Python. We have the formula to calculate the WCI and it's straightforward. We are going to use the following formula to calculate the WCI.Twc(WCI) = 13.12 + 0.6215Ta – 11.37v+0.16 + 0.3965Tav+0.16whereTwc = Wind Chill Index (Based on Celsius temperature scale)Ta = Air Temperature (in degree Celsius)v = Wind Speed (in miles per hour)We are going to use the math module function wherever we need them. Using the math module function decreases the execution time of a program.Follow the below steps to complete the program.Import the math moduleInitialize the ... Read More

Different Methods to find Prime Number in Python Program

Hafeezul Kareem
Updated on 24-Apr-2020 12:39:11

1K+ Views

In this tutorial, we are going to explore different methods to find whether a given number is valid or not. Let's start without further due.Method-1It's a general method to find prime numbers.If the number is less than or equal to one, return False.If the number is divisible by any number, then the function will return False.After the loop, return True.Example Live Demo# checking for prime def is_prime(n):    if n

Lambda expression in Python Program to rearrange positive and negative numbers

Hafeezul Kareem
Updated on 24-Apr-2020 12:34:21

824 Views

In this tutorial, we are going to write an anonymous function using lambda to rearrange positive and negative number in a list. We need the pick the negative numbers and then positive numbers from a list to create a new one.AlgorithmLet's see how to solve the problem step by step.1. Initialize a list with negative and positive numbers. 2. Write a lambda expression the takes a list as an argument.    2.1. Iterate over the list and get negative numbers    2.2. Same for positive numbers    2.3. Combine both using concatination operator. 3. Return the resultant list.Note - Use ... Read More

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