All Apex variables, whether they’re class member variables or method variables, are initialized to null. Make sure that you initialize your variables to appropriate values before using them. For example, initialize a Boolean variable to false.
Apex primitive data types include:
Data Type | Description |
---|---|
Blob | A collection of binary data stored as a single object. You can convert this data type to String or from String using the toString and valueOf methods, respectively. Blobs can be accepted as Web service arguments, stored in a document (the body of a document is a Blob), or sent as attachments. For more information, see Crypto Class. |
Boolean | A value that can only be assigned true, false, or
null. For
example:Boolean isWinner = true; |
Date | A value that indicates a particular day. Unlike Datetime values, Date
values contain no information about time. Date values must always be
created with a system static method. You can add or subtract an Integer value from a Date value, returning a Date value. Addition and subtraction of Integer values are the only arithmetic functions that work with Date values. You can’t perform arithmetic functions that include two or more Date values. Instead, use the Date methods. |
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. You can add or subtract an Integer or Double value from a Datetime value, returning a Date value. Addition and subtraction of Integer and Double values are the only arithmetic functions that work with Datetime values. You can’t perform arithmetic functions that include two or more Datetime values. Instead, use the Datetime methods. |
Decimal | A number that includes a decimal point. Decimal is an arbitrary
precision number. Currency fields are automatically assigned the type
Decimal. If you do not explicitly set the number of decimal places
for a Decimal, the item from which the Decimal is created determines
the Decimal’s scale. Scale is a count of decimal
places. Use the setScale
method to set a Decimal’s scale.
|
Double | A 64-bit number that includes a decimal point. Doubles have a minimum
value of -263 and a maximum value of
263-1. For
example:Double d=3.14159; Scientific notation (e) for Doubles is not supported. |
ID | Any valid 18-character Force.com
record identifier. For
example:ID id='00300000003T2PGAA0'; If you set ID to a 15-character value, Apex converts the value to its 18-character representation. All invalid ID values are rejected with a runtime exception. |
Integer | A 32-bit number that does not include a decimal point. Integers have
a minimum value of -2,147,483,648 and a maximum
value of 2,147,483,647. For
example:Integer i = 1; |
Long | A 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. For
example:Long l = 2147483648L; |
Object |
Any data type that is supported in Apex. Apex supports primitive data types (such as Integer), user-defined custom classes, the sObject generic type, or an sObject specific type (such as Account). All Apex data types inherit from Object. You can cast an object that represents a more specific data type to its underlying data type. For example: Object obj = 10; // Cast the object to an integer. Integer i = (Integer)obj; System.assertEquals(10, i); The next example shows how to cast an object to a user-defined type—a custom Apex class named MyApexClass that is predefined in your organization. Object obj = new MyApexClass(); // Cast the object to the MyApexClass custom type. MyApexClass mc = (MyApexClass)obj; // Access a method on the user-defined class. mc.someClassMethod(); |
String | Any set of characters surrounded by single quotes. For example,
String s = 'The quick brown fox jumped over the lazy dog.'; String size: Strings have no 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. Empty Strings and Trailing Whitespace: sObject String field values follow the same rules as in the SOAP API: they can never be empty (only null), and they can never include leading and trailing whitespace. These conventions are necessary for database storage. Conversely, Strings in Apex can be null or empty and can include leading and trailing whitespace, which can be used to construct a message. The Solution sObject field SolutionNote
operates as a special type of String. If you have HTML Solutions
enabled, any HTML tags used in this field are verified before the
object is created or updated. If invalid HTML is entered, an error
is thrown. Any JavaScript used in this field is removed before the
object is created or updated. In the following example, when the
Solution displays on a detail page, the SolutionNote field has H1
HTML formatting applied to it:
trigger t on Solution (before insert) { Trigger.new[0].SolutionNote ='<h1>hello</h1>'; } In
the following example, when the Solution displays on a detail page,
the SolutionNote field only contains
HelloGoodbye:
trigger t2 on Solution (before insert) { Trigger.new[0].SolutionNote = '<javascript>Hello</javascript>Goodbye'; } For more information, see “HTML Solutions Overview” in the Salesforce online help. Escape Sequences: All Strings in Apex use the same escape sequences as SOQL strings: \b (backspace), \t (tab), \n (line feed), \f (form feed), \r (carriage return), \" (double quote), \' (single quote), and \\ (backslash). Comparison Operators: Unlike Java, Apex Strings support using the comparison operators ==, !=, <, <=, >, and >=. Because Apex uses SOQL comparison semantics, results for Strings are collated according to the context user’s locale and are not case-sensitive. For more information, see Operators. String Methods: As in Java, Strings can be manipulated with several standard methods. For more information, see String Class. Apex classes and triggers saved (compiled) using API version 15.0 and higher produce a runtime error if you assign a String value that is too long for the field. |
Time | A value that indicates a particular time. Time values must always be created with a system static method. See Time Class. |
In addition, two non-standard primitive data types cannot be used as variable or method types, but do appear in system static methods:
For more information on the AnyType data type, see Field Types in the Object Reference for Salesforce and Force.com.