大约有 45,000 项符合查询结果（耗时：0.0601秒） [XML]
Difference between string object and string literal [duplicate]
...
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
23...
Environment variables for java installation
...
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?
...
How do I specify new lines on Python, when writing on files?
...
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.
...
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...
Named string formatting in C#
Is there any way to format a string by name rather than position in C#?
18 Answers
18
...
What is “callback hell” and how and why does RX solve it?
Can someone give a clear definition together with a simple example that explains what is a "callback hell" for someone who does not know JavaScript and node.js ?
...