The standard has been changed since the question (and most answers) were posted in the resolution of this defect report. The way to make a for(:) loop work on your type X is now one of two ways: Create member X::begin() and X::end() that return something that acts like an iterator Create a free function … Read more
No, but you can provide your own counter. The reason for this is that the for-each loop internally does not have a counter; it is based on the Iterable interface, i.e. it uses an Iterator to loop through the “collection” – which may not be a collection at all, and may in fact be something … Read more
a++ is known as postfix. add 1 to a, returns the old value. ++a is known as prefix. add 1 to a, returns the new value. C#: string[] items = {“a”,”b”,”c”,”d”}; int i = 0; foreach (string item in items) { Console.WriteLine(++i); } Console.WriteLine(“”); i = 0; foreach (string item in items) { Console.WriteLine(i++); } … Read more
The pythonic way is to use enumerate: for idx, item in enumerate(my_list):
This works with any explorer. document.querySelector(‘input[name=”genderS”]:checked’).value; This is a simple way to get the value of any input type. You also do not need to include jQuery path.
You can use generator expressions like this: gen = (x for x in xyz if x not in a) for x in gen: print(x)
Django provides it. You can use either: {{ forloop.counter }} index starts at 1. {{ forloop.counter0 }} index starts at 0. In template, you can do: {% for item in item_list %} {{ forloop.counter }} # starting index 1 {{ forloop.counter0 }} # starting index 0 # do your stuff {% endfor %} More info … Read more
The newest versions of pandas now include a built-in function for iterating over rows. for index, row in df.iterrows(): # do some logic here Or, if you want it faster use itertuples() But, unutbu’s suggestion to use numpy functions to avoid iterating over rows will produce the fastest code.
No, don’t spoil it with a break. This is the last remaining stronghold for the use of goto.
Each element of the container is a map<K, V>::value_type, which is a typedef for std::pair<const K, V>. Consequently, in C++17 or higher, you can write for (auto& [key, value]: myMap) { std::cout << key << ” has value ” << value << std::endl; } or as for (const auto& [key, value]: myMap) { std::cout << … Read more