static

Initialize static variable with element of const compound literal

由 ≡放荡痞女 提交于 2020-01-06 08:48:17
问题 Is a const compound literal a valid initializer for a static variable? #define COMPOUND ((const int [2]){1, 2}) static const int x = COMPOUND[0]; /* static const int x = 1; should be equivalent */ EDIT: The possible duplicacte in the first comment doesn't make sense, because I'm asking explicitly about const literals, and not variables. 回答1: Yes, an element of a compound literal may be used as an initializer. C 2018 6.7.9 4 tells us what initializers must be: All the expressions in an

Queries count for page in asp.net mvc

由 巧了我就是萌 提交于 2020-01-06 07:25:07
问题 I want to calculate how much queries are executed when i request a page in asp.net mvc. Difficults in page logic: sum queries are executed in main controller action, but others - in widget controller actions, which are called by Html.ActionLink in master page. I wrote base class for all controllers in which i'm encapsulate query called function to increase queries counter - static variable. On page loading it work nice, all queries are counted, but when i requested second page my static

Using the same variables in two threads, but I don't know why they won't update in Java

由 一曲冷凌霜 提交于 2020-01-06 01:27:06
问题 I would like to start off by saying that I know there are similar questions to this. I did some searching, and I DID find some information. Unfortunately, the solutions did not help me. I do not know why. This is why I ask this question. I have two Threads I am working with in Java. I have four classes that are related to this. The first class is the class with the 'main' method in it. It sets up and starts all the Threads. Here is how I start and declare the Threads: Thread thread1 = new

does creating instance of the same class in the main mathod creates two instances?

由 孤街浪徒 提交于 2020-01-05 14:12:51
问题 The title might be too long but i'll explain myself. Usually, when I creates a main mathod, i put it in the class that i start with. Lately i have seen other people codes and saw that they put the main mathod in a new class. I thought about it and this question came in my mind. When i start the program, does instance of the class that contains the main mathod is created? So when I create a new instance of the same class in the main mathod, will it create 2 instances or the main is not related

does creating instance of the same class in the main mathod creates two instances?

由 你离开我真会死。 提交于 2020-01-05 14:12:14
问题 The title might be too long but i'll explain myself. Usually, when I creates a main mathod, i put it in the class that i start with. Lately i have seen other people codes and saw that they put the main mathod in a new class. I thought about it and this question came in my mind. When i start the program, does instance of the class that contains the main mathod is created? So when I create a new instance of the same class in the main mathod, will it create 2 instances or the main is not related

Magento CMS Page/Static Blocks - How to display store name?

由 北战南征 提交于 2020-01-05 12:16:23
问题 I have number of Magento CMS pages and static blocks which use the variable {{store url=""}} to display the store url address in some text depending which store is being viewed. I would like to also display the store name. Is there an equivalent which would display the store name, something like {{store name=""}}? ({{store name=""}} doesn't work btw) I don't have access to the .php files so would like to know if this is possible without access. If not, then I can request changes to the .php,

Static Attributes in Java

由 爱⌒轻易说出口 提交于 2020-01-05 08:37:17
问题 public class Ride { public static String name; public static int ticketsRequired; public static float heightRequirement; public Ride(String name, int ticketsRequired, float heightRequirement) { this.name = name; this.ticketsRequired = ticketsRequired; this.heightRequirement = heightRequirement; } public static void main(String args[]) { Ride coaster, tosser; coaster = new Ride("Roller Coaster", 6, 4.25f); tosser = new Ride("Tummy Tosser", 7, 4.9f); } } It only takes the value of the last

Should I make a method static

由 ε祈祈猫儿з 提交于 2020-01-05 08:05:28
问题 I've read a few threads related to the question by I'm still not sure what's better for the current situation. I have two simple classes: File: string name; long size; Folder: string name; IList<File> files; IList<Folder> folders; If I want to implement a method which calculates the contents size of a folder, should I implement it as an instance or as a static member. The implementation needs a Folder object as a sole parameter and it does not change any state of the variable so I'm thinking

Java 面向对象 --单例模式

由 孤人 提交于 2020-01-05 07:26:53
在长期的程序设计过程中，开发者们总结出了很多设计经验，最终经过整理和优化，变成了如今的设计模式； 设计模式有很多 有单例，工厂，代理等等。这里推荐一本关于Java设计模式的书籍 Head First设计模式 今天我们这里讲解的是最常用的单例模式； 在Java应用中，单例对象能保证在一个JVM中，该对象只有一个实例存在； 有两种实现，一种是饿汉式，一种是懒汉式； 我们上下代码，先上 饿汉式实现： package com.java1234.chap03.sec18; public class Singleton { /** * 构造方法私有 */ private Singleton(){ } /** * 饿汉式单例实现 */ private static final Singleton single=new Singleton(); /** * 获取实例 */ public static Singleton getInstance(){ return single; } } 这里我们构造方法私有 这样就保证了在外部是无法来实例化对象； 然后我们先在内部定义一个静态常量对象，然后再写一个static方法 来返回这个对象，这样就保证是一个对象了； package com.java1234.chap03.sec18; public class Test { public static

java的单例设计模式

由 扶醉桌前 提交于 2020-01-05 07:26:39
单例设计模式是java的一种设计模式，它是指在设计一个类时，要保证在整个程序运行期间针对该类内存中只存在一个实例对象。 单例设计模式包括饿汉式和懒汉式两种模式。 饿汉式：类一加载进内存就创建好了对象； 饿汉式的代码如下： package com.sjk.sheng; /** * 单例模式之饿汉式 * @author sjk * */ public class Single { //将构造函数私有化，不让别的类建立该类对象 private Single(){} //自己建立一个对象 private static final Single s = new Single(); //提供一个公共访问方式 public static Single getInstance() { return s; } } 懒汉式：类加载进内存的时候，对象还没有存在，只有调用了getInstance()方法时，对象才开始创建。 懒汉式的代码如下： package com.sjk.sheng; /** * 单例模式之懒汉式 * @author sjk * */ public class Single { private Single(){} private static Single s; public static Single getInstance() { if(s==null) /
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