Apex Developer Guide
Summer '26 (API version 67.0)
Spring '26 (API version 66.0)
Winter '26 (API version 65.0)
Summer '25 (API version 64.0)
Spring '25 (API version 63.0)
Winter '25 (API version 62.0)
Summer '24 (API version 61.0)
Spring '24 (API version 60.0)
Winter '24 (API version 59.0)
Summer '23 (API version 58.0)
Spring '23 (API version 57.0)
Winter '23 (API version 56.0)
Summer '22 (API version 55.0)
Spring '22 (API version 54.0)
Winter '22 (API version 53.0)
Summer '21 (API version 52.0)
Spring '21 (API version 51.0)
Winter '21 (API version 50.0)
Summer '20 (API version 49.0)
Spring '20 (API version 48.0)
Winter '20 (API version 47.0)
Summer '19 (API version 46.0)
Spring '19 (API version 45.0)
Winter '19 (API version 44.0)
Summer '18 (API version 43.0)
Spring '18 (API version 42.0)
Winter '18 (API version 41.0)
Summer '17 (API version 40.0)
Spring '17 (API version 39.0)
Winter '17 (API version 38.0)
Summer '16 (API version 37.0)
Spring '16 (API version 36.0)
Winter '16 (API version 35.0)
Summer '15 (API version 34.0)
Spring '15 (API version 33.0)
Winter '15 (API version 32.0)
Spring '14 (API version 30.0)
Release Notes
Data Types
Primitive Data Types
Sets
Maps
Parameterized Typing
Enums
Variables
Constants
Assignment Statements
Rules of Conversion
Apex Reference
Glossary
Newer Version Available
Collections
Collections in Apex can be lists, sets, or maps.
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Lists
A list is an ordered collection of elements that are distinguished by their indices. List elements can be of any data type—primitive types, collections, sObjects, user-defined types, and built-in Apex types. -
Sets
A set is an unordered collection of elements that do not contain any duplicates. Set elements can be of any data type—primitive types, collections, sObjects, user-defined types, and built-in Apex types. -
Maps
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. -
Parameterized Typing
Apex, in general, is a statically-typed programming language, which means users must specify the data type for a variable before that variable can be used.