What will the following code print when run? public class TestClass { public static void main(String[] args) throws Exception { String[] sa = {“a”, “b”, “c”}; for(String s : sa){ if(“b”.equals(s)) continue; System.out.println(s); if(“b”.equals(s)) break; System.out.println(s+” again”); } } } To determine the output you have to run through the loop one iteration at a … Leggi tutto
in Java, the order for initialization statements is as follows: PRIMA TUTTE LE COSE STATIC (sia fields che statements) NELL’ORDINE ESATTO IN CUI SONO INSERITI static variables and static initializers in order. instance variables and instance initializers in order. constructors. First, static statements/blocks are called IN THE ORDER they are defined. Next, instance initializer statements/blocks … Leggi tutto
Byte A byte can ALWAYS be assigned to an int. Range of byte -128 to 127 Char A char value can ALWAYS be assigned to an int variable, since the int type is wider than the char type. char c = 320 is valid because 320 is below the maximum value that a char can … Leggi tutto
class A { public void perform_work(){} } class B extends A { public void perform_work(){} } class C extends B { public void perform_work(){} } How can you let perform_work() method of A to be called from an instance method in C? Standard Tests – Last Day Test (Unique) : 2022-07-12 17:54 Q 28 of 72 Mark … Leggi tutto
The Role of Exceptions: An exception is Java’s way of saying, “I give up. I don’t know what to do right now. You deal with it.” Notice that you’re using two different keywords here: throw tells Java that you want to throw an Exception. throws simply declares that the method might throw an … Leggi tutto
Install Redux Toolkit and React-Redux npm install @reduxjs/toolkit react-redux Create a Redux Store import { configureStore } from ‘@reduxjs/toolkit’ export const store = configureStore({ reducer: {}, }) Provide the Redux Store to React import React from ‘react’ import ReactDOM from ‘react-dom’ import ‘./index.css’ import App from ‘./App’ import { store … Leggi tutto
Methods and Encapsulation: APPUNTI: Studia i metodi astratti e native Studia instanceOf studia gli operatori Encapsulation State e eredità https://docs.oracle.com/javase/tutorial/java/IandI/multipleinheritance.html Ereditarietà multipla di stato, implementazione e tipo Una differenza significativa tra classi e interfacce è che le classi possono avere campi mentre le interfacce no. Inoltre, puoi creare un’istanza di una classe per creare un oggetto, … Leggi tutto
Prima solo le class components possono avere lo State in un component. Ma ora con i React HOOKS i functional component è cambiato tutto le class component: import React, { Component } from ‘react’ class AppTest extends Component { render() { return ( Hello i’m class component ) } } export default AppTest Functional component: … Leggi tutto
Context: an alternative to passing props
This this serve a disambiguare. Mettiamo il caso che creiamo un costruttore con i parametri, e passiamo i parametri con lo stesso nome degli attributi della classe che vogliamo inizializzare, this serve a dire a Java che ci riferiamo all’attributo e non al parametro in ingresso del costruttore. public class Persona(){ private String nome; private … Leggi tutto