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What is Type-safe?
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Type safety means that the compiler will validate types while compiling, and throw an error if you try to assign the wrong type to a variable.
Some simple examples:
// Fails, Trying to put an integer in a string
String one = 1;
// Also fails.
int foo = "bar";
This also applies to method argume...
Python exit commands - why so many and when should each be used?
It seems that python supports many different commands to stop script execution. The choices I've found are: quit() , exit() , sys.exit() , os._exit()
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Read an Excel file directly from a R script
... directly into R? Or should I first export the data to a text- or CSV file and import that file into R?
12 Answers
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Writing to an Excel spreadsheet
... to write some data from my program to a spreadsheet. I've searched online and there seem to be many packages available (xlwt, XlsXcessive, openpyxl). Others suggest to write to a .csv file (never used CSV and don't really understand what it is).
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Check synchronously if file/directory exists in Node.js
...version of lstat, etc.
lstatSync tells you both whether something exists, and if so, whether it's a file or a directory (or in some file systems, a symbolic link, block device, character device, etc.), e.g. if you need to know if it exists and is a directory:
var fs = require('fs');
try {
// Q...
Difference between signed / unsigned char [duplicate]
So I know that the difference between a signed int and unsigned int is that a bit is used to signify if the number if positive or negative, but how does this apply to a char ? How can a character be positive or negative?
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How to use LINQ to select object with minimum or maximum property value
... Probably a little slower than just implementing IComparable and using Min (or a for loop). But +1 for a O(n) linqy solution.
– Matthew Flaschen
May 27 '09 at 6:07
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Should one use < or
...!= instead? I'd say that that most clearly establishes i as a loop counter and nothing else.
– yungchin
Feb 12 '09 at 2:59
21
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What is the difference between persist() and merge() in JPA and Hibernate?
What is the difference between persist() and merge() in Hibernate?
4 Answers
4
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How do browsers pause/change Javascript when tab or window is not active?
...st is quite CPU intensive. requestAnimationFrame is not supported by IE 9- and Opera 12-.
The test logs the actual time it takes for a setInterval and requestAnimationFrame to run in different browsers, and gives you the results in the form of a distribution. You can change the number of millisecon...