JAVA Archives - Petamind https://petaminds.com/tag/java/ A.I, Data and Software Engineering Tue, 05 Oct 2021 06:08:47 +0000 en-US hourly 1 https://wordpress.org/?v=6.9.4 https://petaminds.com/wp-content/uploads/2019/09/ic_launcher.png JAVA Archives - Petamind https://petaminds.com/tag/java/ 32 32 WHY DO WE NEED TO OVERRIDE EQUALS AND HASHCODE METHODS IN JAVA/Kotlin https://petaminds.com/why-do-we-need-to-override-equals-and-hashcode-methods-in-java-kotlin/ https://petaminds.com/why-do-we-need-to-override-equals-and-hashcode-methods-in-java-kotlin/#comments Fri, 19 Mar 2021 02:12:56 +0000 https://petaminds.com/?p=2889 In this post, we will discuss why it is important to override equals and hashCode method in Java/Kotlin. Item 9 in Josh Bloch’s Effective Java suggests always override hashCode() method if the class overrides equals(). In this post, we will discuss why this is necessary and good practice.  We know that two objects are considered equal only if their references […]

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]]> https://petaminds.com/why-do-we-need-to-override-equals-and-hashcode-methods-in-java-kotlin/feed/ 1 Tutorial: Multi-touch gesture for android https://petaminds.com/tutorial-multi-touch-gesture-for-android/ https://petaminds.com/tutorial-multi-touch-gesture-for-android/#comments Fri, 23 Oct 2020 03:34:21 +0000 https://petaminds.com/?p=2853 Multi-touch gestures are very useful in many common scenarios, such as zooming, panning. For game development, handling multi-touch is essential. This post will give a quick guide for handling multi-touch points. Project structure We create a new project name MultiTouch with Java and add a new class named GameScene as a subclass of android.view.View. The […]

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]]> https://petaminds.com/tutorial-multi-touch-gesture-for-android/feed/ 2 Asteroid Collision Solution – Leetcode coding challenge https://petaminds.com/asteroid-collision-solution-leetcode-coding-challenge/ https://petaminds.com/asteroid-collision-solution-leetcode-coding-challenge/#respond Fri, 02 Oct 2020 01:57:00 +0000 https://petaminds.com/?p=2845 The following asteroid collision problem is from Leetcode. The problem We are given an array asteroids of integers representing asteroids in a row. For each asteroid, the absolute value represents its size, and the sign represents its direction (positive meaning right, negative meaning left). Each asteroid moves at the same speed. Find out the state of the […]

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]]> https://petaminds.com/asteroid-collision-solution-leetcode-coding-challenge/feed/ 0 Touch me if you can (V.0.1)- Hero vs monsters game https://petaminds.com/touch-me-if-you-can-v-0-1-hero-vs-monsters-game/ https://petaminds.com/touch-me-if-you-can-v-0-1-hero-vs-monsters-game/#respond Tue, 25 Aug 2020 07:30:12 +0000 https://petaminds.com/?p=2661 This is a (very) simple JAVA implementation of the game “hero vs monsters” as part of the year 1 BSE lab. The implementation is mainly for demonstrating the custom view and touch event. Video tutorial is at the end of the article. The UI it will be a very simple UI with only one view […]

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]]> https://petaminds.com/touch-me-if-you-can-v-0-1-hero-vs-monsters-game/feed/ 0 Top programming languages to learn 2020-2021 https://petaminds.com/top-programming-languages-to-learn-2020-2021/ https://petaminds.com/top-programming-languages-to-learn-2020-2021/#comments Thu, 30 Jul 2020 22:38:00 +0000 https://petaminds.com/?p=2475 “What is the best programming language to learn” is generally not a good question. A language should bind to a purpose, developing environment. Set it aside, popular languages often come with trending jobs. Here is the list of top 7 programming languages to consider in 2020 and 2021. 1.  Python The programming language continues to […]

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]]> https://petaminds.com/top-programming-languages-to-learn-2020-2021/feed/ 2 Create a trainable chatbot with java https://petaminds.com/how-to-create-a-simple-trainable-chatbot-with-java/ https://petaminds.com/how-to-create-a-simple-trainable-chatbot-with-java/#respond Thu, 16 Apr 2020 02:12:20 +0000 https://petaminds.com/?p=2356 A chatbot is a software application used to conduct an on-line chat conversation via text or text-to-speech, in lieu of providing direct contact with a live human agent. This article will demonstrate a short fun coding piece to simulate a chatbot. Its objectives are: Accept input from the console as a string and give an answer If the bot cannot find […]

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]]> https://petaminds.com/how-to-create-a-simple-trainable-chatbot-with-java/feed/ 0 Fun coding challenge: print the American flag https://petaminds.com/fun-coding-challenge-print-the-american-flag/ https://petaminds.com/fun-coding-challenge-print-the-american-flag/#comments Fri, 25 Oct 2019 21:40:40 +0000 https://petaminds.com/?p=1514 Printing is an important part when programming. Printing the US flag to the system console was a small part of “the shape game” for kids, in which the players will select the correct name for a given shape. Basic Requirements: You are required to print the American flag to the console using just “*” and […]

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]]> https://petaminds.com/fun-coding-challenge-print-the-american-flag/feed/ 2 Check if a string is a palindrome https://petaminds.com/check-if-a-string-is-a-palindrome/ https://petaminds.com/check-if-a-string-is-a-palindrome/#respond Sun, 04 Aug 2019 22:46:59 +0000 https://petaminds.com/?p=2620 A palindrome is a word, number, phrase, or other sequence of characters which reads the same backward as forward, such as madam, racecar. There are also numeric palindromes, including date/time stamps using short digits 11/11/11 11:11 and long digits 02/02/2020. Sentence-length palindromes ignore capitalization, punctuation, and word boundaries, so “A man, a plan, a canal, Panama!” is treated as AMANAPLANACANALPANAMA. Example 1: Input: "A man, a […]

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]]> https://petaminds.com/check-if-a-string-is-a-palindrome/feed/ 0 String interpolation in different programming languages https://petaminds.com/string-interpolation-in-different-programming-languages/ https://petaminds.com/string-interpolation-in-different-programming-languages/#comments Mon, 03 Dec 2018 10:19:11 +0000 http://petaminds.com/?p=343 This article quickly lists out several example to create and manipulate a string from data in different programming languages.

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]]> https://petaminds.com/string-interpolation-in-different-programming-languages/feed/ 3 Random seed https://petaminds.com/random-seed/ https://petaminds.com/random-seed/#respond Sat, 10 Nov 2018 00:29:22 +0000 http://petaminds.com/?p=332 if you want to have control to the random sequence or let other people to generate the same sequence of random numbers, take a seed.

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