Salesforce Collections.

Salesforce Collections 

(List, Set & Map)

List:

→ List is a collection of elements, Such as primitive data types (String, Integer, Date, etc), user defined objects, sObjects, Apex objects or other collections (can be multidimensional up to 5 levels).

→ List allows duplicate values.

→ List index position starts from zero.

Syntax: List<datatype> listName = new List <datatype>();

List Methods:

1. add()

→ Add value in List.

→ Ex.

     List <string> fruits = new List <string>();

     fruits.add('Apple');

     fruits.add('Orange');

     fruits.add('Banana');

     fruits.add('Grape');

OR

List <string> fruits = new List <string>{'Apple','Orange','Banana','Grape'};

2. get()

→ Retrieve a value from the list using Index.

→ Ex.

     String getfruit = fruits.get(1);

          - We get 'Orange' fruit form list using getfruit variable.

3. set()

→ Replace a value with the value at given Index parameter.

→ Ex.

     fruits.set(3,'Strawberry');  

          - In List value has been changed at the index 3. 'Grape' is replace to 'Strawberry'

4. size()

→ Return the number of elements in the List.

→ Ex.

     fruits.size();

          - Give the size of fruits list is 3.

5. clear()

→ Remove the elements from the list.

→ Ex.

     fruits.clear();          

For more List methods.

Set:

→ Set is a collection of unique, unordered elements.

→ It can contain primitive data types (String, Integer, Date, etc) or sObjects.

→ Set allows unique values.

Syntax: Set<datatype> SetName = new Set <datatype>();

Set Methods:

1. add()

→ Adds an element to the set if it is not already present.

2. contains()

→ Returns true if the set contains the specified element.

3. equals()

→ Compares this set with the specified set and returns true if both sets are equal; otherwise, returns false.

4. size()

→ Returns the number of elements in the set.

5. remove()

→ Removes the specified element from the set if it is present. 

For more Set methods

Map:

→ Map is a collection of key-value pair.

→ Keys can be any primitive data types (String, Integer, Date, etc) while values can include primitives, Apex objects, sObjects and other collections.

→ Map allows duplicate values, but each key must be unique.

Syntax: map<datatype,datatype> MapName = new map <datatype,datatype>();

Map Methods:

1. get(key)

→ Returns the value to which the specified key is mapped, or null if the map contains no value for this key.

2. put(key, value)

→ Associates the specified value with the specified key in the map.

3. remove(key)

→ Removes the mapping for the specified key from the map, if present, and returns the corresponding value.

4. size()

→ Returns the number of key-value pairs in the map.

5. values()

→ Returns a list that contains all the values in the map.

For more Map methods

Apex - Primitive Data types

Apex - Primitive Data types

• Integer
• Decimal
• Double
• Long
• Date
• Datetime
• String
• ID
• Boolean

       1.      Integer

             → 32-bit number without include decimal point.

             → Ex:

       Integer intNumber = 70;

       system.debug('Value of intNumber variable -> '+ intnumber);

     

     2.      Decimal

           → A number that includes a decimal point.

           → Decimal is an arbitrary precision number.

           → Currency fields are automatically assigned the type Decimal.

        

     3.      Double

           → 64 - bit number that includes a decimal point.

           → Doubles have a minimum value of -2⁶³ and a maximum value of 2⁶³-1

           → Ex:

        double pi = 3.14159;

        system.debug('Value of pi variable -> '+ pi);

     4.      Long

           → 64 - bit number that does not include a decimal point.

           → Longs have a minimum value of -2⁶³ and a maximum value of 2⁶³-1.

           → Use this data type when you need a range of values wider than the range provided by Integer.

           → Ex:

        Long ln = 214748985683648L;

        system.debug('Value of long variable -> '+ ln);

      5.      Date

           → A value that indicates a particular day.

           → Date values not contain information about time.

           → Date values must always be created with a system static method.

           → Ex:

        Date dtDate = date.today();

        System.debug('Today Date -> '+dtDate);

     6.      Datetime

           → A value that indicates a particular day and time, such as a timestamp.

           → Datetime values must always be created with a system static method.

     7.      String

           → Set of meaningful characters surrounded by single quotes.

           → It does not have limit on the number of characters they can include.

           → Instead, the heap size limit is used to ensure that your Apex programs don't grow too large.

           → Strings can be manipulated with several standard methods.

           → Ex:

         String specialStr = 'The quick brown fox jumped over the lazy dog.';

         System.debug('Special string -> ' + specialStr);

     8.      ID

           → Any valid 18-character Force.com record identifier.

           → If you set ID to a 15-character value, Apex converts the value to its 18-character representation.

           → Ex:

           ID id='00300000003T2PGAA0';

     9.      Boolean

           → A value that can only be assigned true, false, or null.

           → This type of variables can be used as flag in programming to identify the particular condition set or not set.

           → Ex:

           Boolean youCan = true;

How to create Custom Object

How to create Custom Object

Step 1: Go to Setup and then search for 'Object' as shown below. Then click on the Objects link as shown below

Step 2: Once the object page is opened, then click on the 'Create New Object' button as shown below

Step 3: After clicking on button, new object creation page will appear and then enter all the object details as entered below. 

→ Object name should be Student. You just have to enter the information in the field as shown in below screenshot and keep other default things as it is.

→ Enter the information and then click on 'Save' button

→ By following above steps, we have successfully created the "Student" object.

Creating the Custom Fields for Student object

Step 1: We will be creating a field named as 'Mobile Number' of data type as Number. Go to Setup and click on it.

Step 2: Search for 'Object' as shown below and click on it

Step 3: Click on object 'Student'.

Step 4: Once you have clicked on Student object link and the object detail page appears, click on the New button.

Step 5: Then select the data type as Number and click next.

Step 6: Enter the field name and label as shown below

Step 7: Click on Visible and then click Next.

→ Click on 'Save' button.

→ By following above steps, our custom field 'Mobile Number' is created. 
→ You have to follow all above custom field creation steps for remaining fields. 

→ This is the final view of "Student" object once all field are created.

How to create developer account in salesforce

How to create developer account in salesforce

Step:1 Write below URL in browser address panel.

           https://developer.salesforce.com/signup

   

    → Fill all required information in sign up page.
    → Write regular Email id, which is used to confirm your developer account.
    → Write unique "Username".
    → Last click "Sign me up" button. 

• If all information are valid and correct, then you can see below screen.

Step: 2 Kindly check your Email Inbox, You have received one mail, to confirm your developer account.

Step: 3 Click "Verify Account" button for confirm your account.

    → After clicking button, you will move to "Password" set up page. 

Step: 4 Write new password and confirm your password, then click "Change Password" button. your developer account successfully created.

• Now, Using "UserName" and "Password" you can logged in your salesforce dev account.

Login URL → https://login.salesforce.com/