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Why use apparently meaningless do-while and if-else statements in macros?
...macro wrapped in what seems like a meaningless do while loop. Here are examples.
9 Answers
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How to validate an Email in PHP?
...ER_VALIDATE_EMAIL) !== false;
}
Note: For other uses (where you need Regex), the deprecated ereg function family (POSIX Regex Functions) should be replaced by the preg family (PCRE Regex Functions). There are a small amount of differences, reading the Manual should suffice.
Update 1: As pointed o...
Preserving signatures of decorated functions
Suppose I have written a decorator that does something very generic. For example, it might convert all arguments to a specific type, perform logging, implement memoization, etc.
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Does the ternary operator exist in R?
...s the latest evaluation, if-else is equivalent to ?:.
> a <- 1
> x <- if(a==1) 1 else 2
> x
[1] 1
> x <- if(a==2) 1 else 2
> x
[1] 2
The power of R is vectorization. The vectorization of the ternary operator is ifelse:
> a <- c(1, 2, 1)
> x <- ifelse(a==1, 1, ...
How to trim a file extension from a String in JavaScript?
For example, assuming that x = filename.jpg , I want to get filename , where filename could be any file name (Let's assume the file name only contains [a-zA-Z0-9-_] to simplify.).
...
C library function to perform sort
...arison function.
It does its magic and your array is sorted in-place. An example follows:
#include <stdio.h>
#include <stdlib.h>
int comp (const void * elem1, const void * elem2)
{
int f = *((int*)elem1);
int s = *((int*)elem2);
if (f > s) return 1;
if (f < s) r...
Shortest distance between a point and a line segment
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How to mock the Request on Controller in ASP.Net MVC?
...q:
var request = new Mock<HttpRequestBase>();
// Not working - IsAjaxRequest() is static extension method and cannot be mocked
// request.Setup(x => x.IsAjaxRequest()).Returns(true /* or false */);
// use this
request.SetupGet(x => x.Headers).Returns(
new System.Net.WebHeaderCollect...
What is the difference between . (dot) and $ (dollar sign)?
...aring after it will take precedence over anything that comes before.
For example, let's say you've got a line that reads:
putStrLn (show (1 + 1))
If you want to get rid of those parentheses, any of the following lines would also do the same thing:
putStrLn (show $ 1 + 1)
putStrLn $ show (1 + 1)...
C++形参与实参的区别（实例解析） - C/C++ - 清泛网 - 专注C/C++及内核技术
...改变，而实参中的值不会变化。
参考如下示例：
void Exchg1(int x, int y)
{
int tmp;
tmp=x;
x=y;
y=tmp;
printf("Exchg1:x=%d,y=%d\n",x,y);
}
void Exchg2(int &x, int &y)
{
int tmp;
tmp=x;
x=y;
y=tmp;
printf("Exchg2:x=%d,y=%d\n",x,y);
}
void Exchg3(int *...