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What's the difference between echo, print, and print_r in PHP?
...s you have in your variables. Consider this test program:
$values = array(0, 0.0, false, '');
var_dump($values);
print_r ($values);
With print_r you can't tell the difference between 0 and 0.0, or false and '':
array(4) {
[0]=>
int(0)
[1]=>
float(0)
[2]=>
bool(false)
[3]=...
VC MFC工具栏(CToolBar)控件 - C/C++ - 清泛网 - 专注C/C++及内核技术
...钮控件显示的区域（大小）相对于父窗口
ButtonRect.left=10;
ButtonRect.top=10;
ButtonRect.right=80;
ButtonRect.bottom=30;
m_Button.Create("动态创建",WS_CHILD,ButtonRect,this,1115);
m_Button.ShowWindow(SW_SHOW);//显示按钮控件
知道了怎样动态创建按钮控件，...
How do Python's any and all functions work?
...or example,
>>> multiples_of_6 = (not (i % 6) for i in range(1, 10))
>>> any(multiples_of_6)
True
>>> list(multiples_of_6)
[False, False, False]
Here, (not (i % 6) for i in range(1, 10)) is a generator expression which returns True if the current number within 1 and 9 i...
How to get the name of the calling method?
...
puts caller[0]
or perhaps...
puts caller[0][/`.*'/][1..-2]
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Why does struct alignment depend on whether a field type is primitive or user-defined?
...est = new RefAndTwoInt32Wrappers();
test.text = "adsf";
test.x.x = 0x11111111;
test.y.x = 0x22222222;
Console.ReadLine(); // <=== Breakpoint here
When the breakpoint hits, use Debug + Windows + Memory + Memory 1. Switch to 4-byte integers and put &test in the Address f...
How to generate a random integer number from within a range
...rong. Returning rand() % N does not uniformly give a number in the range [0, N) unless N divides the length of the interval into which rand() returns (i.e. is a power of 2). Furthermore, one has no idea whether the moduli of rand() are independent: it's possible that they go 0, 1, 2, ..., which is...
Using comparison operators in Scala's pattern matching system
....e. an if and a boolean expression after the pattern:
a match {
case 10 => println("ten")
case x if x > 10 => println("greater than ten")
case _ => println("less than ten")
}
Edit: Note that this is more than superficially different to putting an if after the =>, becaus...
How to create circle with Bézier curves?
...
10 Answers
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R - Concatenate two dataframes?
... line adds column b to data frame b.
Results
> a <- data.frame(a=c(0,1,2), b=c(3,4,5), c=c(6,7,8))
> a
a b c
1 0 3 6
2 1 4 7
3 2 5 8
> b <- data.frame(a=c(9,10,11), c=c(12,13,14))
> b
a c
1 9 12
2 10 13
3 11 14
> b$b <- NA
> b
a c b
1 9 12 NA
2 10 13 NA
3 11...
How to add an empty column to a dataframe?
...t; df = pd.DataFrame({"A": [1,2,3], "B": [2,3,4]})
>>> df
A B
0 1 2
1 2 3
2 3 4
>>> df["C"] = ""
>>> df["D"] = np.nan
>>> df
A B C D
0 1 2 NaN
1 2 3 NaN
2 3 4 NaN
...