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Generate random string/characters in JavaScript
I want a 5 character string composed of characters picked randomly from the set [a-zA-Z0-9] .
77 Answers
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Conveniently map between enum and int / String
... int
yourEnum.ordinal()
int → enum
EnumType.values()[someInt]
String → enum
EnumType.valueOf(yourString)
enum → String
yourEnum.name()
A side-note:As you correctly point out, the ordinal() may be "unstable" from version to version. This is the exact reason why I always stor...
Show percent % instead of counts in charts of categorical variables
... shows what additional columns are added to the data frame by ggplot2. All extra columns are of the form ..variable...
– Ramnath
May 17 '14 at 13:42
1
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Multiple queries executed in java in single statement
...s, and no. Any other value is rejected at runtime with an SQLException.
String dbUrl = "jdbc:mysql:///test?allowMultiQueries=true";
Unless such instruction is passed, an SQLException is thrown.
You have to use execute( String sql ) or its other variants to fetch results of the query executio...
How can I initialize base class member variables in derived class constructor?
...ase from Member idiom. It's not a code free solution, you'd have to add an extra layer of inheritance, but it gets the job done. To avoid boilerplate code you could use boost's implementation
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Understanding exactly when a data.table is a reference to (vs a copy of) another data.table
... <- DT[,new:=1L]
because the RHS already changed DT by reference. The extra DT <- is to misunderstand what := does. You can write it there, but it's superfluous.
DT is changed by reference, by :=, EVEN WITHIN FUNCTIONS :
f <- function(X){
X[,new2:=2L]
return("something else")
}...
Check if an element is present in an array [duplicate]
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!==-1 [extra chars]
– Francisc
Aug 7 '13 at 12:22
3
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Remove NA values from a vector
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?max shows you that there is an extra parameter na.rm that you can set to TRUE.
Apart from that, if you really want to remove the NAs, just use something like:
myvec[!is.na(myvec)]
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Why always ./configure; make; make install; as 3 separate steps?
...he commands to compile a program and installation was left to the user. An extra rule allows make install to place the compiled output in a place that might be correct; there are still plenty of good reasons that you might not want to do this, including not being the system administrator, not want t...
Placeholder in UITextView
...HolderTextView : UITextView
@property (nonatomic, retain) IBInspectable NSString *placeholder;
@property (nonatomic, retain) IBInspectable UIColor *placeholderColor;
-(void)textChanged:(NSNotification*)notification;
@end
UIPlaceHolderTextView.m:
#import "UIPlaceHolderTextView.h"
@interface UI...