What is map keySet return apex?
keySet() Returns a set that contains all of the keys in the map. put(key, value) Associates the specified value with the specified key in the map.
What is map in Apex?
A map is a collection of key-value pairs where each unique key maps to a single value. Keys and values can be any data type—primitive types, collections, sObjects, user-defined types, and built-in Apex types.
How do I pass a map list in Apex?
Once you have instantiated a map, you can add values to the map simply by using the put() method. However, if you happen to have a list of sObjects you can just pass that list in the constructor like so: Map accountsById = new Map(listOfAccounts);
What can a map key contain in apex?
Map keys and values can contain any collection, and can contain nested collections. For example, you can have a map of Integers to maps, which, in turn, map Strings to lists. Map keys can contain up to only four levels of nested collections.
How to make a duplicate map in apex?
Map Methods 1 clear () Removes all of the key-value mappings from the map. 2 clone () Makes a duplicate copy of the map. 3 containsKey (key) Returns true if the map contains a mapping for the specified key. 4 deepClone () Makes a duplicate copy of a map, including sObject records if this is a map with sObject record values.
What kind of hash structure does apex use?
Apex uses a hash structure for all maps. The iteration order of map elements is deterministic. You can rely on the order being the same in each subsequent execution of the same code. However, we recommend to always access map elements by key.
Why are repeat and square brackets used in apex?
Check spelling because the map key is automatically used by the apex:repeat and square brackets are the expression language way of looking up a value in a map. See this answer for some examples of how the ordering of the keys is now more predictable.