SEARCH KEYWORD -- Integer di
Hexadecimal and long in Java
Today I encountered a hexadecimal operation problem when I was implementing a bit reverse function for integer type. Basically in the implementation, there is an operation which is to do the bit operation & between one long integer and a hexadecimal number 0x00000000FFFFFFFFF. I was expecting that the high 32 bits of the long integer will be zeroed. But unfortunately I didn't get the expected result. The basic implementation is: long num=0x00F0_0000; num = (num>>16) | (num<<16); ...
Hexadecimal,long,Java,bitwise operation 2014-06-18 23:44:32
What will the value of Integer.valueOf(127) == Integer.valueOf(127) be in Java?
Do you really understand how Java does the integer comparison? OK, ignore the statements in the post title. What we are interested in is another set of comparison statements. Let's first see below code snippet. public class IntegerComparison { public static void main(String[] args) { Integer a = 127, b = 127; Integer c = 128, d = 128; System.out.println(a == b); System.out.println(c == d); } } What do you think the output will be? Are they both displaying true? You will find out t...
ByteBuffer in Java
ByteBuffer is introduced in java.nio since Java 1.4. It provides a way of representing raw structured data such as from a file or from network. It enables fast access of underlying data compared to traditional ways like byte[] Prior to Java 1.4, if you want to represent a structured raw data, you need to create a byte[] and then having a set of checks to delimit the byte array to get the expected tokens. There are three ways to create a ByteBuffer: Wrapping an exiting array by calling ByteBuffe...
JAVA,BYTEBUFFER,ALLOCATION 2015-07-08 03:17:44
Data type in MySQL
For both small free database space and large e-commerce websites, reasonable database table structure design is essential. To achieve this, it requires us to have a full understanding of commonly used data types in database system. Below we share some knowledge about data types in MySQL.1. Numeric typesThe numeric types can be classified as : integer, float and decimal type.The so-called "decimal" refers DECIMAL and NUMERIC, they are of the same type. Strictly speaking it is not a numeric type, ...
Smuggling data in pointers
While reading up on The ABA Problem I came across a fantastic hack. The ABA problem, in a nutshell, results from the inability to atomically access both a pointer and a "marked" bit at the same time (read the wikipedia page). One fun, but very hackish solution is to "smuggle" data in a pointer. Example:#include "stdio.h"void * smuggle(void * ptr, int value){ return (void *)( (long long)ptr | (value & 3) );}int recoverData(void * ptr){ return (long long)ptr &...
Why no max/min function for integer in GoLang
You may notice that there is no max/min function provided to compare the maximum/minimum of two or more integers if you are a GoLang developer with some experience . In other languages, these functions are provided as part of the core lib functions. Have you wondered why? Indeed GoLang provides max/min function in math package, but they are used for comparing float64 data type. The signature of these two functions are math.Min(float64, float64) float64 math.Max(float64, float64) float...
Case sensitivity in PHP
Case sensitivity in PHP is a bit messy. We recommend that you stick to the case sensitive rule in any language. Here we share some case sensitivity cases in PHP.1. Case sensitive1.1 Variable name is case sensitiveAll variables names are case sensitive, these include normal variables and superglobals such as $_GET,$_POST,$_REQUEST,$_COOKIE,$_SESSION,$_GLOBALS etc.<?php$abc = 'abcd';echo $abc; //Output 'abcd'echo $aBc; //No outputecho $ABC; //No output1.2 Constant name by default is case sensit...
PHP,Case sensitivity,Summary 2012-06-25 05:48:17
Understand more about Go basics with one interview question
First, let's take a look at below Go interview question: package main const s = "Go101.org" // len(s) == 9 // 1 << 9 == 512 // 512 / 128 == 4 var a byte = 1 << len(s) / 128 var b byte = 1 << len(s[:]) / 128 func main() { println(a, b) } What would be the output in your mind? The output would be 4 0. Surprising? Before getting to the output values, some concepts in Go need to be introduced and explained in more detail. len() len() is a built-in function in Go to get t...
GOLANG,CONSTANT,SHIFT OPERATION,LEN() 2020-10-10 02:52:19
Stream API in Java 8
Overview In this lesson on Stream API in Java, we will study how we can put Streams to use to write efficient and much more maintainable code. We will also write code with and without Streams so that we are able to compare the two versions. Before doing all this, we must know how to create a Stream and process it and that is what we will get started with. Introduction to Streams We will be starting with creating Streams. Let us get started with the Stream<T> API which enables us to play w...
STREAM API,JAVA 8,DEVELOPMENT,TEAM 2018-01-30 00:14:46
20 Database Design Best Practices
Use well defined and consistent names for tables and columns (e.g. School, StudentCourse, CourseID ...).Use singular for table names (i.e. use StudentCourse instead of StudentCourses). Table represents a collection of entities, there is no need for plural names.Don’t use spaces for table names. Otherwise you will have to use ‘{‘, ‘[‘, ‘“’ etc. characters to define tables (i.e. for accesing table Student Course you'll write “Student Cour...
Database design,20 tips,Well defined name,Design pattern 2012-02-07 12:10:48
RECENT
- Streamlining the Project Invoicing Process: Tools and Strategies
- Performance comparison of string concatenation in Go language
- Why init() is not recommended in Go
- The Role of Coding Skills in Advancing Tech Careers
- Tips for Socializing With Friends During College
- Proximity Cards Do More Than Just Open Doors
- How to choose quality painted auto parts
- Oval engagement rings from MoonOcean: Elegance of form and individual approach
- Hologres vs AWS Redshift
- GoLand connect to Hologres
- more>>