大约有 47,000 项符合查询结果(耗时:0.0563秒) [XML]

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Should I use pt or px?

What is the difference between pt and px in CSS? Which one should I use and why? 5 Answers ...
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How do I use boolean variables in Perl?

... @BlueWaldo: you can also use cmp and <=> when comparing and assigning the results of the comparison to a scalar. $var = $var1 cmp $var2; 'cmp' and '<=>' (used for numeric comparisons) returns -1, 0, or 1 if left argument is less than, equal to,...
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What do 'real', 'user' and 'sys' mean in the output of time(1)?

What do 'real', 'user' and 'sys' mean in the output of time? 6 Answers 6 ...
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Finding the number of days between two dates

...I think returning a negative number of days provides relevant information. And you should be using $your_date-$now, if you want a future date to return a positive integer. – Tim Mar 2 '12 at 18:49 ...
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What are bitwise shift (bit-shift) operators and how do they work?

I've been attempting to learn C in my spare time, and other languages (C#, Java, etc.) have the same concept (and often the same operators) ... ...
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Why does jQuery or a DOM method such as getElementById not find the element?

...ers parse HTML documents from top to bottom. Elements are added to the DOM and scripts are (generally) executed as they're encountered. This means that order matters. Typically, scripts can't find elements which appear later in the markup because those elements have yet to be added to the DOM. Cons...
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delete vs delete[] operators in C++

What is the difference between delete and delete[] operators in C++? 7 Answers 7 ...
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What's the difference between `on` and `live` or `bind`?

... vs delegate. In future versions of jQuery, these methods will be removed and only on and one will be left. Examples: // Using live() $(".mySelector").live("click", fn); // Equivalent `on` (there isn't an exact equivalent, but with good reason) $(document).on("click", ".mySelector", fn); // ...
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How to avoid isset() and empty()

I have several older applications that throw a lot of "xyz is undefined" and "undefined offset" messages when running on the E_NOTICE error level, because the existence of variables is not explicitly checked using isset() and consorts. ...
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Does PostgreSQL support “accent insensitive” collations?

...r now This approach is more efficient as other solutions floating around, and safer. Create an IMMUTABLE SQL wrapper function executing the two-parameter form with hard-wired schema-qualified function and dictionary. Since nesting a non-immutable function would disable function inlining, base it o...