大约有 48,000 项符合查询结果(耗时:0.0451秒) [XML]

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What does “Could not find or load main class” mean?

... The java <class-name> command syntax First of all, you need to understand the correct way to launch a program using the java (or javaw) command. The normal syntax1 is this: java [ <options> ] <class-name> [<arg> ...] where &...
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Does Java SE 8 have Pairs or Tuples?

I am playing around with lazy functional operations in Java SE 8, and I want to map an index i to a pair / tuple (i, value[i]) , then filter based on the second value[i] element, and finally output just the indices. ...
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What is the difference between gravity and layout_gravity in Android?

I know we can set the following values to the android:gravity and android:layout_gravity properties: 20 Answers ...
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Solving a “communications link failure” with JDBC and MySQL [duplicate]

... in different web sites, but non of them worked. Finally I changed my code and found out what was the problem. I'll try to tell you about different approaches and sum them up here. While I was seeking the internet to find the solution for this error, I figured out that there are many solutions that...
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What is the difference between linear regression and logistic regression?

...ut as probabilities but it's a mistake because the output can be negative, and greater than 1 whereas probability can not. As regression might actually produce probabilities that could be less than 0, or even bigger than 1, logistic regression was introduced. Source: http://gerardnico.com/wiki/dat...
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How to set or change the default Java (JDK) version on OS X?

... @MattO'Brien it’s something which depends on the shell you’re using, and the configuration you have in place, so I can’t give a complete solution for that… – markhellewell Nov 14 '14 at 2:25 ...
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How do I resolve git saying “Commit your changes or stash them before you can merge”?

...made some updates on my local machine, pushed them to a remote repository, and now I'm trying to pull the changes to the server and I get the message; ...
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COUNT(*) vs. COUNT(1) vs. COUNT(pk): which is better? [duplicate]

... Bottom Line Use either COUNT(field) or COUNT(*), and stick with it consistently, and if your database allows COUNT(tableHere) or COUNT(tableHere.*), use that. In short, don't use COUNT(1) for anything. It's a one-trick pony, which rarely does what you want, and in those ...
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Why avoid increment (“++”) and decrement (“--”) operators in JavaScript?

... My view is to always use ++ and -- by themselves on a single line, as in: i++; array[i] = foo; instead of array[++i] = foo; Anything beyond that can be confusing to some programmers and is just not worth it in my view. For loops are an exception,...
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Using try vs if in python

...er LBYL style ("look before you leap"). To me, it's a matter of efficiency and readability. In your example (say that instead of returning a list or an empty string, the function were to return a list or None), if you expect that 99 % of the time result will actually contain something iterable, I'd...