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Test for existence of nested JavaScript object key

... Update Looks like lodash has added _.get for all your nested property getting needs. _.get(countries, 'greece.sparta.playwright') https://lodash.com/docs#get Previous answer lodash users may enjoy lodash.contrib which has a couple methods that mitigate ...
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Which SQL query is faster? Filter on Join criteria or Where clause?

... # explain analyze select e.* from event e join result r on e.id = r.event_id and r.team_2_score=24; QUERY PLAN -------------------------------------------------------------------------------------...
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Creating a blocking Queue in .NET?

...ublic class BlockingQueue<T> { private readonly Subject<T> _queue; private readonly IEnumerator<T> _enumerator; private readonly object _sync = new object(); public BlockingQueue() { _queue = new Subject<T>(); _enumerator = _queue.GetEnume...
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Benchmarking (python vs. c++ using BLAS) and (numpy)

....1 Dot product benchmark Code: import numpy as np a = np.random.random_sample((size,size)) b = np.random.random_sample((size,size)) %timeit np.dot(a,b) Results: System | size = 1000 | size = 2000 | size = 3000 | netlib BLAS | 1350 ms | 10900 ms | 39200 ms | ...
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What is “android.R.layout.simple_list_item_1”?

...ayout.html (Updated link thanks @Estel: https://github.com/android/platform_frameworks_base/tree/master/core/res/res/layout ) You can actually view the code for the layouts. share | improve this an...
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How can mixed data types (int, float, char, etc) be stored in an array?

...y elements a discriminated union, aka tagged union. struct { enum { is_int, is_float, is_char } type; union { int ival; float fval; char cval; } val; } my_array[10]; The type member is used to hold the choice of which member of the union is should be used for e...
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RegEx for Javascript to allow only alphanumeric

...rs here. for example: /^([a-zA-Z0-9\u0600-\u06FF\u0660-\u0669\u06F0-\u06F9 _.-]+)$/ this will support persian. share | improve this answer | follow | ...
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Allowed characters in Linux environment variable names

...EE Std 1003.1-2001 consist solely of uppercase letters, digits, and the '_' (underscore) from the characters defined in Portable Character Set and do not begin with a digit. Other characters may be permitted by an implementation; applications shall tolerate the presence of such names. ...
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How do I check if there are duplicates in a flat list?

...e set() to remove duplicates if all values are hashable: >>> your_list = ['one', 'two', 'one'] >>> len(your_list) != len(set(your_list)) True share | improve this answer ...
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How to implement “select all” check box in HTML?

...: for each...in is actually valid Javascript: developer.mozilla.org/en/Core_JavaScript_1.5_Reference/… But, as porneL has pointed out, it's an obscure construct. Also, this code doesn't work in Safari 5 or Chrome 5. It works in FF 3.6, and IIRC, it worked in Safari 4. for(var i in checkboxes) chec...