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Why is it Valid to Concatenate Null Strings but not to Call “null.ToString()”?
...
The first sample will be translated into:
var bob = String.Concat("abc123", null, null, null, "abs123");
The Concat method checks input and translate null as an empty string
The second sample will be translated into:
var wtf = ((object)null).ToString();
So a null reference exception will ...
What are the details of “Objective-C Literals” mentioned in the Xcode 4.4 release notes?
...;
number = [NSNumber numberWithChar:'X'];
number = [NSNumber numberWithInt:12345];
number = [NSNumber numberWithUnsignedLong:12345ul];
number = [NSNumber numberWithLongLong:12345ll];
number = [NSNumber numberWithFloat:123.45f];
number = [NSNumber numberWithDouble:123.45];
number = [NSNumber numberWi...
Does MSTest have an equivalent to NUnit's TestCase?
...a4b5", "345")]
[DataRow("3&5*", "35")]
[DataRow("123", "123")]
public void StripNonNumeric(string before, string expected)
{
string actual = FormatUtils.StripNonNumeric(before);
Assert.AreEqual(expected, actual);
}
}
Again, V...
Regular expression to match numbers with or without commas and decimals in text
... are embedded in other text. IMHO anything that fails to pull 1,234.56 and 1234—and only those numbers—out of abc22 1,234.56 9.9.9.9 def 1234 is a wrong answer.
First of all, if you don't need to do this all in one regex, don't. A single regex for two different number formats is hard to maintain...
通信连接组件 · App Inventor 2 中文网
...开浏览器到指定的网页。 假设您要访问的页面是“www.fun123.cn”（您可以随意替换自己的选择），将属性设置为：
Action: android.intent.action.VIEW
DataUri: http://www.fun123.cn
调用第三方地图也可以使用这个启动器：
...
Remove commas from the string using JavaScript
...aximumFractionDigits: 2
})
// Good Inputs
parseFloat(numFormatter.format('1234').replace(/,/g,"")) // 1234
parseFloat(numFormatter.format('123').replace(/,/g,"")) // 123
// 3rd decimal place rounds to nearest
parseFloat(numFormatter.format('1234.233').replace(/,/g,"")); // 1234.23
parseFloat(numFo...
correct way to define class variables in Python [duplicate]
...u'll see it more clearly with some code:
class MyClass:
static_elem = 123
def __init__(self):
self.object_elem = 456
c1 = MyClass()
c2 = MyClass()
# Initial values of both elements
>>> print c1.static_elem, c1.object_elem
123 456
>>> print c2.static_elem, c2.ob...
How to pattern match using regular expression in Scala?
...Regex(sc.parts.mkString, sc.parts.tail.map(_ => "x"): _*)
}
scala> "123" match { case r"\d+" => true case _ => false }
res34: Boolean = true
Even better one can bind regular expression groups:
scala> "123" match { case r"(\d+)$d" => d.toInt case _ => 0 }
res36: Int = 123
sc...
App Inventor 2 列表代码块 · App Inventor 2 中文网
...异常、报错。
如果给定列表是一个二维列表，如 [["abc","123"],["xyz","456"]] ，则返回的列表项也是一个列表对象，如 ["abc","123"]。
求对象在列表中的位置
返回指定对象在列表中的位置，从 1 开始，如果不在列表中，则返回 0。
...
Difference between final and effectively final
...ited Aug 3 '18 at 16:13
user10111237
answered Jan 5 '14 at 19:32
Suresh AttaSuresh Atta
...