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The difference between bracket [ ] and double bracket [[ ]] for accessing the elements of a list or
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The R Language Definition is handy for answering these types of questions:
http://cran.r-project.org/doc/manuals/R-lang.html#Indexing
R has three basic indexing operators, with syntax displayed by the following examples
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How do I check CPU and Memory Usage in Java?
...e two OperatingSystemMXBean classes. One is the interface provided in java.lang. But there is also another version, that extends this one in com.sun.management. That's the method I was referring to is from that OperatingSystemMXBean
– Ishnark
May 27 '17 at 18:2...
Debugging in Clojure? [closed]
...of local bindings to their values."
[]
(let [symbols (map key @clojure.lang.Compiler/LOCAL_ENV)]
(zipmap (map (fn [sym] `(quote ~sym)) symbols) symbols)))
(declare *locals*)
(defn eval-with-locals
"Evals a form with given locals. The locals should be a map of symbols to
values."
[locals...
Comparing strings by their alphabetical order
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You can call either string's compareTo method (java.lang.String.compareTo). This feature is well documented on the java documentation site.
Here is a short program that demonstrates it:
class StringCompareExample {
public static void main(String args[]){
String s...
How to pass an object from one activity to another on Android
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@MustafaGüven But i am getting classCastException: java.lang.Long by doing so. Can you please explain why?
– Shajeel Afzal
Jun 17 '13 at 19:06
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Oracle TNS names not showing when adding new connection to SQL Developer
...edited Dec 15 '11 at 8:10
Peter Lang
49.3k2626 gold badges138138 silver badges152152 bronze badges
answered Jan 8 '09 at 19:56
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Why do Objective-C files use the .m extension?
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It stands for "methods". From the comp.lang.objective-C FAQ:
The organisation of Objective-C source is typically similar to that of C or C++ source code, with declarations and object interfaces going into header files named with a .h extension, and definitions...
Why is 128==128 false but 127==127 is true when comparing Integer wrappers in Java?
...h can be configured to another value, with the system property.
-Djava.lang.Integer.IntegerCache.high=999
If you run your program with that system property, it will output true!
The obvious conclusion: never rely on two references being identical, always compare them with .equals() method.
S...
Array initializing in Scala
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scala> val arr = Array("Hello","World")
arr: Array[java.lang.String] = Array(Hello, World)
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Difference between string object and string literal [duplicate]
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A String literal is a Java language concept. This is a String literal:
"a String literal"
A String object is an individual instance of the java.lang.String class.
String s1 = "abcde";
String s2 = new String("abcde");
String s3 = "abcde";
All are...