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How to prevent a dialog from closing when a button is clicked
I have a dialog with EditText for input. When I click the "yes" button on dialog, it will validate the input and then close the dialog. However, if the input is wrong, I want to remain in the same dialog. Every time no matter what the input is, the dialog should be automatically closed when I clic...
Difference between string object and string literal [duplicate]
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When you use a string literal the string can be interned, but when you use new String("...") you get a new string object.
In this example both string literals refer the same object:
String a = "abc";
String b = "abc";
System.out.println(a == b);...
CSS force image resize and keep aspect ratio
I am working with images, and I ran across a problem with aspect ratios.
23 Answers
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What can you use Python generator functions for?
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Generators give you lazy evaluation. You use them by iterating over them, either explicitly with 'for' or implicitly by passing it to any function or construct that iterates. You can think of generators as returning multiple items, as if they return a list, but instead of retur...
Environment variables for java installation
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Java SE Development Kit 8u112 on a 64-bit Windows 7 or Windows 8
Set the following user environment variables (== environment variables of type user variables)
JAVA_HOME : C:\Program Files\Java\jdk1.8.0_112
JDK_HOME : %JAVA_HOME%
JRE_HOME : ...
How do I use NSTimer?
... lists guides for the topic being documented (if any exist). For example, with NSTimer, the documentation lists two companion guides:
Timer Programming Topics for Cocoa
Threading Programming Guide
For your situation, the Timer Programming Topics article is likely to be the most useful, whilst th...
Python __str__ versus __unicode__
...seen classes override __unicode__() more frequently than __str__() but it doesn't appear to be consistent. Are there specific rules when it is better to implement one versus the other? Is it necessary/good practice to implement both?
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How do I specify new lines on Python, when writing on files?
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It depends on how correct you want to be. \n will usually do the job. If you really want to get it right, you look up the newline character in the os package. (It's actually called linesep.)
Note: when writing to files using...
How does the “final” keyword in Java work? (I can still modify an object.)
In Java we use final keyword with variables to specify its values are not to be changed.
But I see that you can change the value in the constructor / methods of the class. Again, if the variable is static then it is a compilation error.
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Is there “0b” or something similar to represent a binary number in Javascript
...inary (prefix 0b), octal (prefix 0o) and hexadecimal (prefix: 0x) numeric literals:
var bin = 0b1111; // bin will be set to 15
var oct = 0o17; // oct will be set to 15
var oxx = 017; // oxx will be set to 15
var hex = 0xF; // hex will be set to 15
// note: bB oO xX are all valid...