Apex Non Developers Flashcards
Attributes
Which describe properties (nouns or adjectives). They are characteristics of the class
access modifier, data type, unique name
public String name;
public String height;
Methods
Which describe behavior (verbs)
Actions performed by a class
Methods of the human class
Walk, Talk, work
Attributes of the human class
Toes, Fingers, Hands, Name
Instantiation
Creating an object from a class
Instantiation requires?
class name,
object name,
new keyword,
class name with parentheses
Method declaration syntax includes
An access modifier, a data type or void, a unique method name, a pair of parentheses, a code block with curly braces
public void walk(){
}
Attribute declaration syntax includes
An access modifier, a data type, a unique name
A Method can either return?
1) Void or
2) A single data type: which could be a collection
- -Use the return keyword to pass back a value
Primitives
basic building blocks and cannot be broken down
String firstname = ‘Adam’;
Composites
Non-primitive data types that are built from other data types. Often see the keyword new.
Human man1 = new Human(); Human woman1 - new Human();
A Method can either return?
Void or
A single data type: which could be a collection
–Use the return keyword to pass back a value
When you see a composite being declared what do you usually see?
the keyword new
How do you pass in parameters to a method
You can pass attributes as parameters into a method inside of the ()
The method declaration must supply:
1)a data type that indicates what type of data the method should expect
2)a local variable name that will accept the incoming data
Instantiate an object from the BankAcct class called chkAcct
chkAcct BankAcct = new chkAcct();
Set the attribute accttype of the object chkAcct to Checking
chkAcct.accttype = ‘Checking’;
Set the attribute acctName of the object chkAcct to D.Castillo-Chk
chkAcct.acctName = ‘D.Castillo-Chk’
Invoke the makeDeposit method for $150
chkAcct.makeDeposit(150);
What is a list?
An ordered collection of data of one data type distinguished by its index
Each element in a list contains what 2 pieces of information
An index: an integer that always starts at 0
A value: The data
Whenever you’re looking at a parentheses you’re looking at
A Method
Declare a method that does not return anything and takes one input parameter of a Candidate list object called candsFromTrigger
public void createContact (List candsFromTrigger){
What does the List for loop do?
It iterates over all of the elements in a list one by one with the help of an iteration variable
What is an sObject?
standard or custom objects that store record data in the force.com database
How do developers refer to sObjects and fields
By API names
An sObject variable represents
a row of data and can only be declared in Apex using the SOAP API name of the object
Instantiate an sObject
Account a = new Account();
DML Operations
saving changes to records in the database Insert Update Upsert Delete
DML can operate on?
A single sObject or a list of sObject
Database.insert
Database is the class. .insert is the method
Instantiate an object called acct from the sObject Account class
Account acct = new Account();
Set the attribute name of the acct object to Recruiting
acct.name=’Recruiting’;
Instantiate an object called heese from the sObject Account class
Account heese = new Account();
SOQL
Salesforce Object Query Language
What is the difference between SOQL and SQL
It’s querying sObjects which is an abstraction layer away from the Database
What can SOQL expressions return
A single record
A list of records
An Integer, when using an aggregate function across records
What is a trigger
an apex script that executes before or after a DML operation on a single sObject
What do triggers have that determine when the trigger will execute
Before and After events
What is Trigger.new and Trigger.old
Attributes that provide access to the old and new versions of the sObject records. Trigger is a class.
Triggers execute when
Records are saved through the UI or Web Services API
Instantiate an object called cc from the class CreateContactFromCan
CreateContactFromCan cc = new CreateContactFromCan();
Declare a method that does not return anything called createContact
public void createContact (){
}
Instantiate an object from the BankAcct class called chkAcct
BankAcct chkAcct = new BankAcct();
Set the attribute accttype of the object chkAcct to Checking
chkAcct.accttype = ‘Checking’;
Instantiate an object from the BankAcct class called savAcct
BankAcct savAcct = new BankAcct();
Instantiate an BankAcct List object from the List class called bankAccts
List bankAccts = new List();
Add the chkAcct object to the bankAccts list
bankAccts.add(chkAcct);
Instantiate a Contact list object from the List class
List conList = new List();
Declare a For List loop to loop through the list bankAccts with an iterationvariable called tempacct
For (BankAcct tempacct:bankAccts){
Declare a For list loop to loop through the input parameter list candsFromTrigger with an iterationvariable called currentCandidate
for(Candidate__c currentCandidate:candsFromTrigger){
Instantiate an object called acct from the sObject Account class
Account acct = new Account();
Set the attribute name of the acct object to Recruiting
acct.name=’Recruiting’;
Persist the acct object to the DB using DML
Database.insert(acct);
Instantiate an object called con from the sObject class contact
Contact con = new Contact()
Add the con object to the conList
conList.add(con);
Instantiate an object called cc from the class CreateContactFromCan
CreateContactFromCan cc = new CreateContactFromCan();
Declare a private integer attribute called balance initalize to zero
private integer balance=0;
Declare a method named makeDeposit that does not return anything and one input parameter of type integer called deposit
public void makeDeposit (integer deposit){
Declare a method named getBalance that returns an integer and no input parameter
public integer getBalance(){
What is system.debug
A special method that you can add to your code to generate output when your code is executed to provide feedback for the developer
Object Oriented Languages are based off
Classes
What is the abstract the intangible?
Class
Classes are where you define
Attributes and Methods
What are classes?
Blueprints used to create objects in Code. Start with a capital Letter
How are objects created from classes?
Insantiation.
Human man1 = New Human()
class name, object name, new keyword, class name with()
Attributes start with?
A lowercase letter
Primitive data type examples
Boolean Integer Date String ID Blob Enum
Where does Apex operate?
In memory, separate from the database
What persists data to the database?
DML
Object names starts with?
A lowercase letter
Where does Apex run
in Memory on the application server
A method always has what at the end?
Parens ()
Each element in a list always contains?
An index that always starts at zero and a value
List for loop syntax
for (iterationVariableDataType iterationVariable : list){
//code
}
for(String currentname : studentList){
}
Whats another way of thinking about list for loops
For each element in my list loop
IterationVariableDataType is always what data type
The data type of your list
Whats the syntax for list for loops
for(type of List currentStudent :StudentList){
}
Attributes are similar to
Fields
Instantiate an object is the equivalent of
Creating a new record in the UI
What map method do you use to get a set of all of the keys
keySet
What map method reruns a list of values in the map
values
Trigger.new
Trigger is a class. New is an attribute
An object is?
An Instance of a class
Trigger.new returns
a list of the new versions of sObjects
Trigger.old returns
a list of the old versions of sObjecfts
