大约有 4,000 项符合查询结果（耗时：0.0227秒） [XML]
Function to clear the console in R and RStudio
I am wondering if there is a function to clear the console in R and, in particular, RStudio I am looking for a function that I can type into the console, and not a keyboard shortcut.
...
How did I get a value larger than 8 bits in size from an 8-bit integer?
...th c = c - 1 and the values remained within the range [-128 ... 127]:
c: -123
c: -124
c: -125
c: -126
c: -127
c: -128 // about to overflow
c: 127 // woop
c: 126
c: 125
c: 124
c: 123
c: 122
Freaky ey? I don't know much about what the compiler does to expressions like i++ or i--. It's likely promo...
Finding Number of Cores in Java
...urn (OS.indexOf("nix") >= 0 || OS.indexOf("nux") >= 0 || OS.indexOf("aix") > 0 );
}
public static boolean isSolaris() {
return (OS.indexOf("sunos") >= 0);
}
public static String getOS(){
if (isWindows()) {
return "win";
} else if (isMac()) {
return "osx";
...
Query-string encoding of a Javascript Object
...");
}
console.log(serialize({
foo: "hi there",
bar: {
blah: 123,
quux: [1, 2, 3]
}
}));
// foo=hi%20there&bar%5Bblah%5D=123&bar%5Bquux%5D%5B0%5D=1&bar%5Bquux%5D%5B1%5D=2&bar%5Bquux%5D%5B2%5D=3
...
HTML.ActionLink vs Url.Action in ASP.NET Razor
...
@Html.ActionLink("link text", "someaction", "somecontroller", new { id = "123" }, null)
generates:
<a href="/somecontroller/someaction/123">link text</a>
and Url.Action("someaction", "somecontroller", new { id = "123" }) generates:
/somecontroller/someaction/123
There is also Ht...
Check if application is installed - Android
...pp")
and the call the following method to check if the app is installed
fun isInstalled(intent:Intent) :Boolean{
val list = context.packageManager.queryIntentActivities(intent, PackageManager.MATCH_DEFAULT_ONLY)
return list.isNotEmpty()
}
...
Insert multiple rows WITHOUT repeating the “INSERT INTO …” part of the statement?
...
INSERT INTO dbo.MyTable (ID, Name)
SELECT 123, 'Timmy'
UNION ALL
SELECT 124, 'Jonny'
UNION ALL
SELECT 125, 'Sally'
For SQL Server 2008, can do it in one VALUES clause exactly as per the statement in your question (you just need to add a comma to separate each value...
How to get the nth occurrence in a string?
...
const string = "XYZ 123 ABC 456 ABC 789 ABC";
function getPosition(string, subString, index) {
return string.split(subString, index).join(subString).length;
}
console.log(
getPosition(string, 'ABC', 2) // --> 16
)
...
How to convert String to Long in Kotlin?
...dix] is not a valid radix for string to number conversion.
public inline fun String.toLong(radix: Int): Long = java.lang.Long.parseLong(this, checkRadix(radix))
4. string.toLongOrNull(10)
Parses the string as a [Long] number and returns the result or null
if the string is not a valid repre...
Check if a string contains a string in C++
...
123
You can try using the find function:
string str ("There are two needles in this haystack.");
...