How to print all key and values from HashMap in Android?
for (Map.Entry<String,String> entry : map.entrySet()) { String key = entry.getKey(); String value = entry.getValue(); // do stuff }
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switching keys and values in a dictionary in python [duplicate]
For Python 3: my_dict2 = {y: x for x, y in my_dict.items()} For Python 2, you can use my_dict2 = dict((y, x) for x, y in my_dict.iteritems())
Is it reasonable to use None as a dictionary key in Python?
Any hashable value is a valid Python Dictionary Key. For this reason, None is a perfectly valid candidate. There’s no confusion when looking for non-existent keys – the presence of None as a key would not affect the ability to check for whether another key was present. Ex: >>> d = {1: ‘a’, 2: ‘b’, … Read more
How to iterate array keys in Javascript?
You need to call the hasOwnProperty function to check whether the property is actually defined on the object itself (as opposed to its prototype), like this: for (var key in widthRange) { if (key === ‘length’ || !widthRange.hasOwnProperty(key)) continue; var value = widthRange[key]; } Note that you need a separate check for length. However, you … Read more
How to iterate through table in Lua?
To iterate over all the key-value pairs in a table you can use pairs: for k, v in pairs(arr) do print(k, v[1], v[2], v[3]) end outputs: pears 2 p green apples 0 a red oranges 1 o orange Edit: Note that Lua doesn’t guarantee any iteration order for the associative part of the table. If … Read more
php: how to get associative array key from numeric index?
You don’t. Your array doesn’t have a key [1]. You could: Make a new array, which contains the keys: $newArray = array_keys($array); echo $newArray[0]; But the value “one” is at $newArray[0], not [1]. A shortcut would be: echo current(array_keys($array)); Get the first key of the array: reset($array); echo key($array); Get the key corresponding to the … Read more
What is difference between const and non const key?
int and const int are two distinct types. std::map<int, float> and std::map<const int, float> are, similarly, different types. The difference between std::map<const int, float> and std::map<int, float> is, to a degree, analogous to the difference between, say, std::map<int, float> and std::map<std::string, float>; you get a fresh map type for each. In the non-const case, the … Read more
android: Softkeyboard perform action when Done key is pressed
Try this editText.setOnEditorActionListener(new OnEditorActionListener() { @Override public boolean onEditorAction(TextView v, int actionId, KeyEvent event) { if(actionId==EditorInfo.IME_ACTION_DONE){ //do something } return false; } });
MongoDB – Multiple $or operations
Mongo 2.0 added an $and operator, so you can do a query like this: db.things.find({$and: [{$or : [{‘a’:1},{‘b’:2}]},{$or : [{‘a’:2},{‘b’:3}]}] }) http://www.mongodb.org/display/DOCS/Advanced+Queries#AdvancedQueries-%24and
Jump to Closing tag in VS Code?
It is possible to do, but either using Ctrl + Shift + P -> “Emmet: Go to Matching Pair” or by manually setting a shortcut for it (Ctrl + K Ctrl + S). Unfortunately there is currently no support for it out of the box.