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How do I check if a variable exists in a list in BASH
...k the validity of a user input.
I want to match the input (say variable x ) to a list of valid values.
14 Answers
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Utility classes are evil? [closed]
...d object-oriented design, most classes should represent a single thing and all of its attributes and operations. If you are operating on a thing, that method should probably be a member of that thing.
However, there are times when you can use utility classes to group a number of methods together ...
TypeError: 'str' does not support the buffer interface
...ype. In py3 plaintext is only a string, and the method outfile.write() actually takes a byte array when outfile is opened in binary mode, so an exception is raised. Change the input to plaintext.encode('utf-8') to fix the problem. Read on if this bothers you.
In py2, the declaration for file.wri...
Select a Dictionary with LINQ
I have used the "select" keyword and extension method to return an IEnumerable<T> with LINQ, but I have a need to return a generic Dictionary<T1, T2> and can't figure it out. The example I learned this from used something in a form similar to the following:
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Get all unique values in a JavaScript array (remove duplicates)
...l loop through the array and leave only those entries that pass the given callback function onlyUnique.
onlyUnique checks, if the given value is the first occurring. If not, it must be a duplicate and will not be copied.
This solution works without any extra library like jQuery or prototype.js.
It w...
Java 8 NullPointerException in Collectors.toMap
The Java 8 Collectors.toMap throws a NullPointerException if one of the values is 'null'. I don't understand this behaviour, maps can contain null pointers as value without any problems. Is there a good reason why values cannot be null for Collectors.toMap ?
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Why is isNaN(null) == false in JS?
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I believe the code is trying to ask, "is x numeric?" with the specific case here of x = null. The function isNaN() can be used to answer this question, but semantically it's referring specifically to the value NaN. From Wikipedia for NaN:
NaN (Not a Number) is...
Types in Objective-C on iOS
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This is a good overview:
http://reference.jumpingmonkey.org/programming_languages/objective-c/types.html
or run this code:
32 bit process:
NSLog(@"Primitive sizes:");
NSLog(@"The size of a char is: %d.", sizeof(char));
NSLog(@"The size of short is: %d.", sizeof(short));
NSLog(@"The si...
How to empty a list?
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This actually removes the contents from the list, but doesn't replace the old label with a new empty list:
del lst[:]
Here's an example:
lst1 = [1, 2, 3]
lst2 = lst1
del lst1[:]
print(lst2)
For the sake of completeness, the slic...
Get value of a string after last slash in JavaScript
...rn value (if (n !== -1)), but in the above since we're adding 1 to it and calling substring, we'd end up doing str.substring(0) which just returns the string.
Using Array#split
Sudhir and Tom Walters have this covered here and here, but just for completeness:
var parts = "foo/bar/test.html".split...