Building Blocks of Apex: Variables & Data Types Explained Simply - Salesforce Apex Tutorial Part 2 to 7 | Code Snippet

Hello Trailblazers,

In this post, I'm sharing the code snippet for Coding with Confidence: The Fun Way to Learn Salesforce Apex tutorial series part 2 to 7 below:

// * Variables & Data Types in Apex

/*

? What is a variable?
* A variable is simply a named storage/memory location that contains a value. In apex, all variables have a "data type".
! Each variable is by default initialized to null

? What is a Data Type?
* Data type is a keyword associated with a variable. It basically represents the type of data which that variable will store.
* List of primitive data types:
* 1. Boolean
* 2. Integer
* 3. Decimal
* 4. Double
* 5. Long
* 6. Date
* 7. Datetime
* 8. Time
* 9. Id
* 10. String
* 11. Object
* 12. Blob

* These are the OOTB or fundamental data types available in apex programming language. Let's talk about each one of them in detail:

? What is a Boolean data type?
* A variable of Boolean data type can store only one of these two values:
* 1. True
* 2. False

* Example of Boolean data type:
*/

/*
one
two
three

*/

// comment

// * In order to declare a variable, we follow the format: <Data Type><space><Variable name><;>
Boolean isQualified;
System.debug('Value of isQualified boolean variable is: ' + isQualified);

isQualified = false; // * Equals (=) means Assignment
System.debug('Value of isQualified boolean variable is: ' + isQualified);

isQualified = true;
System.debug('Value of isQualified boolean variable is: ' + isQualified);

// isQualified = 123;

/*

? What is an Integer data type?
* An Integer data type can store a 32-bit number with no decimal point. It can store value between -2,147,483,648 to 2,147,483,647

* Example of Integer data type:

*/

Integer sum;
System.debug('Value of sum Integer variable is: ' + sum);

sum = 1;
System.debug('Value of sum Integer variable is: ' + sum);

sum = 10;
System.debug('Value of sum Integer variable is: ' + sum);

sum = 2147483647;
System.debug('Value of sum Integer variable is: ' + sum);

sum = -2147483647;
System.debug('Value of sum Integer variable is: ' + sum);

// sum = false;

/*

? What is a Decimal data type?
* A Decimal data type variable can store a number with a decimal point.

* Example of Decimal data type:

*/

Decimal sum;
System.debug('Value of sum Decimal variable is: ' + sum);

sum = 1.0;
System.debug('Value of sum Decimal variable is: ' + sum);

sum = 1.01;
System.debug('Value of sum Decimal variable is: ' + sum);

sum = 1.234567890123456789012345678901234567890123456789;
System.debug('Value of sum Decimal variable is: ' + sum);

sum = -123456789012345678901234567890123456789012345678.9;
System.debug('Value of sum Decimal variable is: ' + sum);

//* Help Article about the field: https://help.salesforce.com/s/articleView?id=000387302&type=1, however we can have 49 digits in total for a variable of type decimal

// * Assiging integer to a decimal
sum = 123;
System.debug('Value of sum Decimal variable is: ' + sum);

// sum = true;

/*
? What is a Double data type?
* A Double data type variable can store a 64-bit number with a decimal point. It can store value between -2^63 to 2^63-1
* Example of Double data type:
*/

Double sum = 3.14;
System.debug('Value of sum Double variable is: ' + sum);

// * Use Double for less precision. For example: Scientific calculations where rounding off can be done. Use Decimal for more precision. For example: Financial calulations where there are no chances of errors. By default, currency fields in Salesforce are stored as decimals.

/*
? What is a Long data type?
* A Long data type variable can store a 64-bit number without a decimal point. It can store value between -2^63 to 2^63-1.
* Example of Long data type:
*/

Long long1 = 1000000000;  // * Valid long value without "L"
Long long2 = 9223372036854775807L;  // * Valid long value with "L" (for clarity)
System.debug('Value of long1 Long variable is: ' + long1);
System.debug('Value of long2 Long variable is: ' + long2);

// * Long can be used when we need a higher range as compared to an integer

/*
? What is a Date data type?
* A Date data type variable can store a date value without any information about time.
* Example of Date data type:
*/

Date date1 = Date.newInstance(1994, 12, 26);
System.debug('Value of date1 Date variable is: ' + date1);
System.debug('Subtracting 1 from date1 variable. Updated value = ' + (date1 - 1));
System.debug('Adding 1 to date1 variable. Updated value = ' + (date1 + 1));

Date dateFromString = Date.valueOf('1994-12-26');
System.debug('Value of dateFromString Date variable is: ' + dateFromString);

System.debug('Date in string without timestamp is: ' + String.valueOf(dateFromString));

System.debug('Today\'s Date is: ' + System.today());

// * Adding two date values
Date date1 = Date.newInstance(1994, 12, 26);
Date date2 = Date.newInstance(1994, 12, 20);
System.debug(date1 + date2);

/*
? What is a Datetime data type?
* A Datetime data type variable can store a datetime value like a timestamp.
* Example of Datetime data type:
*/

Datetime date1 = Datetime.newInstance(1994, 12, 26);
System.debug('Value of date1 Datetime variable is: ' + date1);

Datetime dateFromString = Datetime.valueOf('1994-12-26 23:11:10'); // GMT + 5:30
System.debug('Value of dateFromString Datetime variable is: ' + dateFromString);

System.debug('Date in string without timestamp is: ' + String.valueOf(dateFromString));

/*
? What is a Time data type?
* A Time data type variable can store a time value which indicates a particular time.
* Example of Time data type:
*/

Time time1 = Time.newInstance(14, 25, 60, 100);
System.debug('Value of time1 Time variable is: ' + time1);
System.debug('Value of hour: ' + time1.hour());
System.debug('Value of minute: ' + time1.minute());
System.debug('Value of second: ' + time1.second());
System.debug('Value of millisecond: ' + time1.millisecond());

/*
? What is a ID data type?
* An ID data type variable can store any valid 18-character salesforce record id.
* Example of ID data type:
*/

Id accountId = '001Hy00001D07fwIAB';
System.debug('Value of Id accountId = ' + accountId);

Id accountIdFifteenDigits = '001Hy00001D07fw';
System.debug('Value of Id accountIdFifteenDigits = ' + accountIdFifteenDigits);

accountId = '123456789123456789';

/*
? What is a String data type?
* A String data type variable can store any set of characters surrounded by single quotes. It has no limit on the number of characters, heap size limit is used instead
* Example of String data type:
*/

String name = 'SFDC Stop';
System.debug('Value of String name = ' + name);

String nameWithTrailingWhitespace = 'SFDC Stop   ';
System.debug('Value of String nameWithTrailingWhitespace = ' + nameWithTrailingWhitespace);

String emptyStringWithWhitespace = '     ';
System.debug('Value of String emptyStringWithWhitespace = ' + emptyStringWithWhitespace);

String escapeSequence = '\nSFDC\tStop \\ A blog about salesforce';
System.debug('Value of String escapeSequence = ' + escapeSequence);

String a = 'apple', b = 'mango';
System.debug(a<b);

String c = 'sfdc', d = 'Sfdc';
System.debug(c==d);

/*
? What is a Object data type?
* An Object data type variable can store value of any data type that is supported in apex. All data types inherit from object
* Example of Object data type:
*/

Object num = 10;
System.debug('Value of Object num = ' + num);

Object name = 'SFDC Stop';
System.debug('Value of Object name = ' + name);

Object num1 = 10, num2 = 20;
System.debug('Sum of Object num1 and num2 = ' + (num1 + num2));

Object num1 = 10, num2 = 20;
Integer num1Int = (Integer) num1, num2Int = (Integer) num2;
System.debug('Sum of Integer num1Int and num2Int = ' + (num1Int + num2Int));

/*
? What is a Blob data type?
* An Blob data type variable can store a collection of binary data as a single object. Blob is the short form for Binary Large Object.
* Example of Blob data type: Contents of an image. Blob can be converted to a String and String can be converted to a Blob
*/

Blob b1 = Blob.valueOf('test');
System.debug('Value of Blob b1 = ' + b1);

System.debug('Value of Blob b1 as string = ' + b1.toString());

YouTube Tutorials

You can check out the tutorials below as well:

Building Blocks of Apex: Variables & Data Types Explained Simply - Salesforce Apex Tutorial Part 2

Apex Gotchas! Common Variable Errors (and Writing Comments) - Salesforce Apex Tutorial Part 3

Apex Integer Data Types: Understanding Limits & Avoiding Errors - Salesforce Apex Tutorial Part 4

Unlock Precision in Apex: The Beginner Guide to Decimal Data Type - Salesforce Apex Tutorial Part 5

Apex Double, Long, Date, Datetime & Time Data Types Explained - Salesforce Apex Tutorial Part 6

Apex Id, String, Object and Blob Data Types Decoded - Salesforce Apex Tutorial Part 7

Check out the tutorials and let me know your feedback in the comments down below.

Happy Trailblazing!!