The problem with this pattern is that you'd have to somehow define the value that should be used in case the get() returns null. There certainly are libraries out there and IIRC there are also some newer …

The documentation for map::count says: "Because all elements in a map container are unique, the function can only return 1 (if the element is found) or zero (otherwise)." To retrieve a value from the …

Jun 10, 2013 · 696 To be able to use std::unordered_map (or one of the other unordered associative containers) with a user-defined key-type, you need to define two things: A hash function; this must be …

Check if map contains a key using std::map::find It checks if any element with given key ‘k’ exists in the map and if yes then it returns its iterator else it returns the end of map.

If you really want to use C strings (which, again, you shouldn't), then you need to use const char* instead of char* in your types. And in general How can I use any kind of structure (objects, structs, …

Feb 20, 2015 · ${map['key']} only seems to work for String literal keys -- if the key you're looking up is a variable then ${map[key]} doesn't seem to work. ###Accessing Map entries given a list of keys### …

If you don't need big performance, browsing all the keys on your map (map.entrySet) to get the ones matching your pattern should be enough. If you need good performance, a solution i have used to …

The original JS map stringifies the key and I am not wanting to do the same type of stringify hack with the new ES6 Map. What can I do to use arrays as keys reliably for a ES6 Map?

Dec 30, 2013 · I want to use tuple consisting of int,char,char in my unordered_map. I am doing like this: #include <string> #include <unordered_map> #include <cstring> #include <iostream> #

Sep 2, 2012 · Can anyone point me to an example of how to use a Map in Groovy which has a String as its key and a List as value?