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How can I check if a file exists in Perl?
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Test whether something exists at given path using the -e file-test operator.
print "$base_path exists!\n" if -e $base_path;
However, this test is probably broader than you intend. The code above will generate output if a plain file exists at that ...
When is a language considered a scripting language? [closed]
...tead of compiled". That would make PHP (for example) a scripting language. Is that the only criterion? Or are there other criteria?
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What is Normalisation (or Normalization)?
Why do database guys go on about normalisation?
10 Answers
10
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What is the difference between -viewWillAppear: and -viewDidAppear:?
What is the difference between -[UIViewController viewWillAppear:] and -[UIViewController viewDidAppear:] ?
12 Answers
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Undefined behavior and sequence points
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C++98 and C++03
This answer is for the older versions of the C++ standard. The C++11 and C++14 versions of the standard do not formally contain 'sequence points'; operations are 'sequenced before' or 'unsequenced' or 'indeterminately sequence...
How to find time complexity of an algorithm
...size of its input, and then simplify the expression to the largest (when N is very large) term and can include any simplifying constant factor.
For example, lets see how we simplify 2N + 2 machine instructions to describe this as just O(N).
Why do we remove the two 2s ?
We are interested in the ...
What exactly is a reentrant function?
Most of the times , the definition of reentrance is quoted from Wikipedia :
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if A vs if A is not None:
...; should return False or True, or their integer equivalents 0 or 1. When this method is not defined, __len__() is called, if it is defined, and the object is considered true if its result is nonzero. If a class defines neither __len__() nor __nonzero__(), all its instances are considered true.
On ...
What are the advantages of using nullptr?
This piece of code conceptually does the same thing for the three pointers (safe pointer initialization):
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What is the default initialization of an array in Java?
...thing in a Java program not explicitly set to something by the programmer, is initialized to a zero value.
For references (anything that holds an object) that is null.
For int/short/byte/long that is a 0.
For float/double that is a 0.0
For booleans that is a false.
For char that is the null char...