Tag Archives: arrays

Java exercise with ArraysList and returning a boolean expresion

Questions: I’m stack doing this exercise. I don’t know how to implement the code inside the boolean teach() and check if teacher can teach programmer. Here is the question and the code: Create a class Programmer with: public method Collection<String> getLanguages –> return all languages that the programmer knows public method void addLanguage(String Language) –>… Read More »

Does escape analysis help JVM to allocate arrays on stack?

Questions: In brief, this is what I do : public void method(List<Integer> elems) { final int MAX_ELEM_COUNT = 32; ByteBuffer bb == ByteBuffer.allocate(MAX_ELEM_COUNT * Integer.BYTES); for (Integer elem : elems) { bb.putInt(elem); } bb.flip(); ByteBuffer dest = getPermanentBufferForSize(bb.remaining()); dest.put(bb); } Temporary buffer is quite small(128 bytes) and it’s not escaping so looks like a good… Read More »

Java : Arrays.parallelSort on int[] using none standard comparator

Questions: For the current implementation I’m using an array of integers, Integer[], to use an external comparator. The order is not the ‘natural’ one but one defined externally. Arrays.parallelSort(Integer[] array, Comparator<T> cmp); Is there a way using parallelSort with an array of integers, int[], and a user defined comparator ? instead , something like :… Read More »

Use JMockit to mock Arrays.sort() methods in a class

Questions: I try to mock Arrays.sort methods to make sure the implementation in the QuickSort class doesn’t make use of Arrays.sort. How can I do this? This is my try, which results in a java.lang.StackOverflowError @Test public void testQuickSort() { Integer[] array = {3, -7, 10, 3, 70, 20, 5, 1, 90, 410, -3, 7,… Read More »

Reactjs – Add, Delete from arrays dynamically

Questions: I have a component which takes input and adds them to a list and displays them: import React, {Component} from ‘react’ import { Form, Col, Label, FormGroup, Button, Alert, Input, Row, } from ‘reactstrap’ export default class NewSubreddit extends Component { constructor(props) { super(props) this.state = {rules: []} } addRule() { const rule =… Read More »

How to read a json file containing multiple arrays?

Questions: I am stuck with how to read a json file which holds multiple arrays. So far i have created three classes first one which just holds the main method in, the second which is called Patients and the third which is called Address. Classes Patients and Address currently have accessor methods within them (getters… Read More »

Php push notification http get request with token and message arrays

Questions: I’m using Push Notification Automate Using PHP to send Notification in Ionic2 TypeScript Android application I’m passing my registration.registrationId to token variable: send() { this.http.get(this.phpPath + ‘sendPushNotification.php?token=’ + token) .map(res => res.json()) .subscribe(data => { console.log(data); }, err => { console.log(err); } ); } to sendPushNotification.php: $registrationIds = array( $_GET[‘token’] ); $msg = array… Read More »

Do arrays in Java store data or pointers

Questions: I was reading about data locality and want to use it to improve my game engine that I’m writing. Let’s say that I have created five objects at different times that are now all in different places in the memory not next to each other. If I add them all to an array, will… Read More »