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Does Java casting introduce overhead? Why?
...t objects of one type to another? Or the compiler just resolves everything and there is no cost at run time?
5 Answers
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Iterating over dictionaries using 'for' loops
...:
will simply loop over the keys in the dictionary, rather than the keys and values. To loop over both key and value you can use the following:
For Python 3.x:
for key, value in d.items():
For Python 2.x:
for key, value in d.iteritems():
To test for yourself, change the word key to poop.
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Split large string in n-size chunks in JavaScript
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As far as performance, I tried this out with approximately 10k characters and it took a little over a second on Chrome. YMMV.
This can also be used in a reusable function:
function chunkString(str, length) {
return str.match(new RegExp('.{1,' + length + '}', 'g'));
}
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What's the fastest way to do a bulk insert into Postgres?
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PostgreSQL has a guide on how to best populate a database initially, and they suggest using the COPY command for bulk loading rows. The guide has some other good tips on how to speed up the process, like removing indexes and foreign keys before loading the data (and adding them back afterward...
Is there a way to add/remove several classes in one single instruction with classList?
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And if you want to apply an Array of several class-names, you have to call: DOMTokenList.prototype.add.apply(elem.classList, ['first', 'second', 'third']);
– Emanuel Kluge
Feb 15 '13 at...
Find a class somewhere inside dozens of JAR files?
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Eclipse can do it, just create a (temporary) project and put your libraries on the projects classpath. Then you can easily find the classes.
Another tool, that comes to my mind, is Java Decompiler. It can open a lot of jars at once and helps to find classes as well.
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Return index of greatest value in an array
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This is probably the best way, since it’s reliable and works on old browsers:
function indexOfMax(arr) {
if (arr.length === 0) {
return -1;
}
var max = arr[0];
var maxIndex = 0;
for (var i = 1; i < arr.length; i++) {
if (arr[i] > m...
Naming conventions for java methods that return boolean(No question mark)
...on the end.
Is the Collection empty?
Does this Node have children?
And, then, true means yes, and false means no.
Or, you could read it like an assertion:
The Collection is empty.
The node has children
Note:
Sometimes you may want to name a method something like createFreshSnapshot?...
What does this symbol mean in JavaScript?
This is a collection of questions that come up every now and then about syntax in JavaScript. This is also a Community Wiki, so everyone is invited to participate in maintaining this list.
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What good are SQL Server schemas?
I'm no beginner to using SQL databases, and in particular SQL Server. However, I've been primarily a SQL 2000 guy and I've always been confused by schemas in 2005+. Yes, I know the basic definition of a schema, but what are they really used for in a typical SQL Server deployment?
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