Articles on Trending Technologies

Technical articles with clear explanations and examples

The new operator in Java

AmitDiwan
AmitDiwan
Updated on 20-Sep-2019 7K+ Views

The new operator is used in Java to create new objects. It can also be used to create an array object.Let us first see the steps when creating an object from a class −Declaration − A variable declaration with a variable name with an object type.Instantiation − The 'new' keyword is used to create the object.Initialization − The 'new' keyword is followed by a call to a constructor. This call initializes the new object.Now, let us see an example −Examplepublic class Puppy {    public Puppy(String name) {       // This constructor has one parameter, name.     ...

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Nested Classes in Java

AmitDiwan
AmitDiwan
Updated on 20-Sep-2019 2K+ Views

Writing a class within another is allowed in Java. The class written within is called the nested class, and the class that holds the inner class is called the outer class. Nested classes are divided into two types −Non-static nested classes (Inner Classes) − These are the non-static members of a class.Static nested classes − These are the static members of a class.Following are the types of Nested classes in Java −Non-static nested classes (Inner Classes)Inner classes are a security mechanism in Java. We know a class cannot be associated with the access modifier private, but if we have the class as a ...

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Check if a value is present in an Array in Java

AmitDiwan
AmitDiwan
Updated on 20-Sep-2019 907 Views

At first sort the array −int intArr[] = {55, 20, 10, 60, 12, 90, 59}; // sorting array Arrays.sort(intArr);Now, set the value to be searched in an int variable −int searchVal = 12;Check for the presence of a value in an array −int retVal = Arrays.binarySearch(intArr, searchVal); boolean res = retVal > 0 ? true : false;Following is an example to check if a value is present in an array −Exampleimport java.util.Arrays; public class Main {    public static void main(String[] args) {       // initializing unsorted int array       int intArr[] = {55, 20, 10, ...

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Check if a String starts with any of the given prefixes in Java

AmitDiwan
AmitDiwan
Updated on 20-Sep-2019 592 Views

Let’s say the string is −String str = "Malyalam";Let’s say the prefixes are in an array −String[] prefixArr = { "Ga", "Ma", "yalam" };Now, to check whether the string starts with any of the abive prefix, use the startsWith() −if (Stream.of(prefixArr)    .anyMatch(str::startsWith))    System.out.println("TRUE"); else    System.out.println("FALSE");Following is an example to check is a string starts with any of the given prefixes −Exampleimport java.util.stream.Stream; class Main {    public static void main(String[] args) {       String str = "Malyalam";       String[] prefixArr = { "Ga", "Ma", "yalam" };       if (Stream.of(prefixArr)     ...

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Check if a string contains only alphabets in Java using ASCII values

AmitDiwan
AmitDiwan
Updated on 20-Sep-2019 542 Views

Let’s say we have set out inut string in myStr variable. Now loop through until the length of string and check for alphabets with ASCII values −for (int i = 0; i < myStr.length(); i++) {    char c = myStr.charAt(i);    if (!(c >= 'A' && c = 'a' && c = 'A' && c = 'a' && c

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Check if a string contains only alphabets in Java using Lambda expression

AmitDiwan
AmitDiwan
Updated on 20-Sep-2019 853 Views

Let’s say our string is −String str = "Amit123";Now, using allMatch() method, get the boolean result whether the string has only alphabets or now −boolean result = str.chars().allMatch(Character::isLetter);Following is an example to check if a string contains only alphabets using Lambda Expressions −Exampleclass Main {    public static void main(String[] args) {       String str = "Amit123";       boolean result = str.chars().allMatch(Character::isLetter);       System.out.println("String contains only alphabets? = "+result);    } }OutputLet us see another example with a different input −String contains only alphabets? = falseExampleclass Main {    public static void main(String[] args) ...

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IlleagalStateException Vs NoSuchElementException in java?

Maruthi Krishna
Maruthi Krishna
Updated on 19-Sep-2019 313 Views

When you call a method at illegal or inappropriate time an IlleagalStateException is generated.For example, the remove() method of the ArrayList class removes the last element after calling the next() or previous methods.After removing the element at the current position you need to move to the next element to remove it i.e. per one call of the next() method you can invoke this remove() method only once.Since the initial position of the list (pointer) will be before the first element, you cannot invoke this method without calling the next method.If you invoke the remove() method otherwise it throws an java.lang.IllegalStateException.Example: ...

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C++ Interview questions based on constructors/ Destructors

sudhir sharma
sudhir sharma
Updated on 19-Sep-2019 1K+ Views

C++ interview questions on ConstructorsWhat is a constructor?A constructor is a function of a class that has the same name as the class. The constructor is called at the time of the initialization of object. There are three types of constructors −Default constructorParameterized constructorCopy constructorSyntaxclass cl_name{    cl_name(){       //This is constructor..    } }What is a destructor?A destructor is a method of a class that has the same name as the class preceded by a tild ~ symbol. It is called at the end of code or when the object is destroyed or goes out of scope.Syntaxclass ...

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C++ vs C#

sudhir sharma
sudhir sharma
Updated on 19-Sep-2019 442 Views

C++ Programming languageA successor of the c programming language that has introduced the concept of classes and objects. It encapsulates features of c and high-level language hence it can be treated as an intermediate-level language. When it was created it was thought of as a C that has classes because of its similarities with C.C# Programming LanguageC# (also known as C sharp) is a general-purpose programming language that was developed by Microsoft to run on .net framework for developing applications for its operating system. It is an object-oriented programming language with features like object-oriented, statically typed, decorative, multiparadigm programming language.Both ...

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C++ program to print unique words in a file

sudhir sharma
sudhir sharma
Updated on 19-Sep-2019 647 Views

A file is a memory location that stores word streams. In a file, there are various words. In this program, we will find all unique words from the file and print them.A unique word means the number of occurrences of the word is one in the file.For example, Tutorials point is best for programming tutorials.Here, the word tutorial occurs more than once, hence it is not unique. Rest all words are unique.AlgorithmTo check for unique words in the given file. Using iterator with two variables : data and occurence. Input : File Step 1 : Read each line from the ...

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