SEARCH KEYWORD -- Integer overflow


  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...

   JAVA,==,EQUALSTO     2018-01-13 22:18:15

  CSS Overflow Property Utilization

Sometimes when we do CSS on HTML elements. We may want to hide some text when the text in a specified box overflows. Usually, we can use a CSS property overflow:hidden to hide the text so that the format of the whole element will not be affected. But will it always work? I believe some of us may encounter problems when we want to hide some text in a table td cell with specified width. If we use td { overflow:hidden;}, it is supposed to hide the text if the text in a td cell overflows. But the fa...

   CSS,Overflow,TD,Cell,Hidden     2014-10-21 08:24:48

  Integer overflow

You may be familiar with integer overflow, but what you may not be familiar with is how gcc handles signed integer overflow. First let's look at the standard, for unsigned integer, the standard says : A computation involving unsigned operands can never overflow, because a result that cannot be represented by the resulting unsigned integer type is reduced modulo the number that is one greater than the largest value that can be represented by the resulting type. In other words, unsigned integer ov...

   Integer overflow,gcc,Linux     2012-10-20 13:33:10

  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, ...

   MySQL, Data type,VARCHAR     2013-01-01 10:56:06

  Be careful about printing error as string in GoLang

In GoLang, we can format and produce string using fmt.Printf(), just like C, GoLang also supports format verbs like %s, %d which can be placeholder for different types of values. But please pay attention when printing error as string so that you will not fall into some trap. Let's first take an example code snippet and see what trap we are talking about. package main import "fmt" type A string func (a A) Error() string { return fmt.Sprintf("%s is an error", a) } func main() { a := A("hello...

   STACKOVERFLOW,GOLANG,FMT     2019-01-23 09:17:15

  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...

   GOLANG,MAX,INT,INT64     2019-06-08 07:00:55

  A simple tutorial about CSS flex property

CSS Flexbox is a layout module that makes it easier to create flexible and responsive layouts in CSS. It provides a simple and powerful way to align elements within a container and distribute space between them. To use flexbox, you need to set the display property of an element to "flex". You can do this by adding the following rule to your CSS: .container { display: flex; } The flex container will now have two main axes: the main axis and the cross axis. By default, the main axis runs horizo...

   JUSTIFY-CONTENT,FLEX,CSS     2022-12-25 06:44:34

  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

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