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Why is address zero used for the null pointer?
In C (or C++ for that matter), pointers are special if they have the value zero: I am adviced to set pointers to zero after freeing their memory, because it means freeing the pointer again isn't dangerous; when I call malloc it returns a pointer with the value zero if it can't get me memory; I use ...
How to check if object (variable) is defined in R?
I'd like to check if some variable is defined in R - without getting an error. How can I do this?
6 Answers
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Does VBA have Dictionary Structure?
Does VBA have dictionary structure? Like keyvalue array?
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What is the $? (dollar question mark) variable in shell scripting? [duplicate]
I'm trying to learn shell scripting, and I need to understand someone else's code. What is the $? variable hold? I can't Google search the answer because they block punctuation characters.
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Code Golf - π day
Guidelines for code-golf on SO
26 Answers
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MySQL JOIN the most recent row only?
I have a table customer that stores a customer_id, email and reference. There is an additional table customer_data that stores a historical record of the changes made to the customer, i.e. when there's a change made a new row is inserted.
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Is there any pythonic way to combine two dicts (adding values for keys that appear in both)?
For example I have two dicts:
17 Answers
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How do I define and use an ENUM in Objective-C?
I declared an enum in my implementation file as shown below, and declared a variable of that type in my interface as PlayerState thePlayerState; and used the variable in my methods. But I am getting errors stating that it is undeclared. How do I correctly declare and use a variable of type PlayerSta...
pdf2htmlEX实现pdf转html - 开源 & Github - 清泛网 - 专注C/C++及内核技术
...下的截图：
windows下载地址：pdf2htmlEX-v1.0-win32-static
本人开发的一个功能：文档在线阅读，要求能够支持移动终端浏览器在线阅读。考虑过将文档先转pdf，然后在将pdf转swf，利用flexpaper在前端浏览器访问。但是由于safari浏...
CentOS 6.4下Squid代理服务器的安装与配置 - 更多技术 - 清泛网 - 专注C/C++及内核技术
CentOS 6.4下Squid代理服务器的安装与配置一、简介代理服务器英文全称是Proxy Server，其功能就是代理网络用户去取得网络信息。Squid是一个缓存Internet 数据的软件，其接收用户的 一、简介
代理服务器英文全称是Proxy Server，其功...