Free Salesforce Developers Tutorials >

Chapter 3 - Apex Datatypes and Operators >

Sets Initialization And Methods

Sets Initialization And Methods

What You’ll Learn


S2 Labs

What Is Set Initialization In Apex?

The way you declare sets is similar to the way you declare lists. You can also have nested sets and sets of lists.

Examples Of Set Initialization In Apex

// Empty set initialized

Set<String> strSet = new Set<String>();

// Set of List of Strings

Set<List<String>> set2 = new Set<List<String>>();

Some Common Methods Of Set In Apex

Following are some common methods of set in Apex:

 

add(element) Adds an element to set and only takes the argument of special datatype while declaring the set. Set<String> s = new Set<String>();
s.add(‘abc’);
s.add(‘ABC’);
s.add(‘abc’);
System.debug(s);//(‘abc’,’ABC’)
addAll(list/set) Adds all of the elements in the specified list/set to the set if they are not already present. List<String> l = new List<String>();
l.add(‘abc’);
l.add(‘def’);
s.addAll(l);
System.debug(s);//(‘abc’,’ABC’,’def’)
clear() Removes all the elements. s.clear();
s.addAll(l);
clone() Makes duplicate of a set. List<String> s2 = s.clone();
System.debug(s);//(‘abc’,’def’)
contains(elm) Returns true if the set contains the specified element. Boolean result = s.contains(‘abc’);
System.debug(result); // true
containsAll(list) Returns true if the set contains all of the elements in the specified list. The list must be of the same type as the set that calls the method. Boolean result = s.containsAll(l);
System.debug(result); // true
size() Returns the size of set. System.debug(s.size()); // 2
retainAll(list) Retains only the elements in this set that are contained in the specified list and removes all other elements. s.add(‘ghi’);
System.debug(s);//(‘abc’,’def’,’ghi’)
s.retainAll(l);
System.debug(s);//(‘abc’,’def’)
remove(elm) Removes the specified element from the set if it is present. s.add(‘ghi’);
s.remove(‘ghi’);
System.debug(s);//(‘abc’,’def’)
removeAll(list) Removes the elements in the specified list from the set if they are present. s.add(‘ghi’);
s.removeAll(l);
System.debug(s);//(‘ghi’)

add(element) Adds an element to set and only takes the argument of special datatype while declaring the set. Set<String> s = new Set<String>();
s.add(‘abc’);
s.add(‘ABC’);
s.add(‘abc’);
System.debug(s);//(‘abc’,’ABC’)
addAll(list/set) Adds all of the elements in the specified list/set to the set if they are not already present. List<String> l = new List<String>();
l.add(‘abc’);
l.add(‘def’);
s.addAll(l);
System.debug(s);//(‘abc’,’ABC’,’def’)
clear() Removes all the elements. s.clear();
s.addAll(l);
clone() Makes duplicate of a set. List<String> s2 = s.clone();
System.debug(s);//(‘abc’,’def’)
contains(elm) Returns true if the set contains the specified element. Boolean result = s.contains(‘abc’);
System.debug(result); // true
containsAll(list) Returns true if the set contains all of the elements in the specified list. The list must be of the same type as the set that calls the method. Boolean result = s.containsAll(l);
System.debug(result); // true
size() Returns the size of set. System.debug(s.size()); // 2
retainAll(list) Retains only the elements in this set that are contained in the specified list and removes all other elements. s.add(‘ghi’);
System.debug(s);//(‘abc’,’def’,’ghi’)
s.retainAll(l);
System.debug(s);//(‘abc’,’def’)
remove(elm) Removes the specified element from the set if it is present. s.add(‘ghi’);
s.remove(‘ghi’);
System.debug(s);//(‘abc’,’def’)
removeAll(list) Removes the elements in the specified list from the set if they are present. s.add(‘ghi’);
s.removeAll(l);
System.debug(s);//(‘ghi’)

salesforce-developer

Download Study Material

Get access to exclusive study material for Salesforce Certification and ace your exams!

Download Now

Our Salesforce Certification Courses

Hey there! Glad you made it through our Salesforce Developer Training for beginners . But wait! We've got some high-in-demand Salesforce courses for you to take your Salesforce skills to the next level, making you a desired professional in the Salesforce job market.

Post a Comment

Your email address will not be published. Required fields are marked *