Switch Statements

Apex provides a switch statement that tests whether an expression matches one of several values and branches accordingly.

The syntax is:

1switch on expression {
2    when value1 {		// when block 1
3        // code block 1
4    }	
5    when value2 {		// when block 2
6        // code block 2
7    }
8    when value3 {		// when block 3
9        // code block 3
10    }
11    when else {		  // default block, optional
12        // code block 4
13    }
14}

The when value can be a single value, multiple values, or sObject types. For example:

1when value1 {
2}

1when value2, value3 {
2}

1when TypeName VariableName {
2}

The switch statement evaluates the expression and executes the code block for the matching when value. If no value matches, the when else code block is executed. If there isn’t a when else block, no action is taken.

There is no fall-through. After the code block is executed, the switch statement exits.

Note

Apex switch statement expressions can be one of the following types.

Integer
Long
sObject
String
Enum

When Blocks

Each when block has a value that the expression is matched against. These values can take one of the following forms.

when literal {} (a when block can have multiple, comma-separated literal clauses)
when SObjectType identifier {}
when enum_value {}

The value null is a legal value for all types.

Each when value must be unique. For example, you can use the literal x only in one when block clause. A when block is matched one time at most.

When Else Block

If no when values match the expression, the when else block is executed.

Salesforce recommends including a when else block, especially with enum types, although it isn’t required. When you build a switch statement using enum values provided by a managed package, your code might not behave as expected if a new version of the package contains additional enum values. You can prevent this problem by including a when else block to handle unanticipated values.

Note

If you include a when else block, it must be the last block in the switch statement.

Examples with Literals

You can use literal when values for switching on Integer, Long, and String types. String clauses are case-sensitive. For example, “orange” is a different value than “ORANGE.”

Single Value Example

The following example uses integer literals for when values.

1switch on i {
2   when 2 {
3       System.debug('when block 2');
4   }
5   when -3 {
6       System.debug('when block -3');
7   }
8   when else {
9       System.debug('default');
10   }
11}

Null Value Example

Because all types in Apex are nullable, a when value can be null.

1switch on i {
2   when 2 {
3       System.debug('when block 2');
4   }
5   when null {
6       System.debug('bad integer');
7   }
8   when else {
9       System.debug('default ' + i);
10   }
11}

Multiple Values Examples

The Apex switch statement doesn’t fall-through, but a when clause can include multiple literal values to match against. You can also nest Apex switch statements to provide multiple execution paths within a when clause.

1switch on i {
2   when 2, 3, 4 {
3       System.debug('when block 2 and 3 and 4');
4   }
5   when 5, 6 {
6       System.debug('when block 5 and 6');
7   }
8   when 7 {
9       System.debug('when block 7');
10   }
11   when else {
12       System.debug('default');
13   }
14}

Method Example

Instead of switching on a variable expression, the following example switches on the result of a method call.

1switch on someInteger(i) {
2   when 2 {
3       System.debug('when block 2');
4   }
5   when 3 {
6       System.debug('when block 3');
7   }
8   when else {
9       System.debug('default');
10   }
11}

Example with sObjects

Switching on an sObject value allows you to implicitly perform instanceof checks and casting. For example, consider the following code that uses if-else statements.

1if (sobject instanceof Account) {
2    Account a = (Account) sobject;
3    System.debug('account ' + a);
4} else if (sobject instanceof Contact) {
5    Contact c = (Contact) sobject;
6    System.debug('contact ' + c);
7} else {
8    System.debug('default');
9}

You can replace and simplify this code with the following switch statement.

1switch on sobject {
2   when Account a {
3       System.debug('account ' + a);
4   }
5   when Contact c {
6       System.debug('contact ' + c);
7   }
8   when null {
9       System.debug('null');
10   }
11   when else {
12       System.debug('default');
13   }
14}

You can use only one sObject type per when block.

Note

Example with Enums

A switch statement that uses enum when values doesn’t require a when else block, but it is recommended. You can use multiple enum values per when block clause.

1switch on season {
2   when WINTER {
3       System.debug('boots');
4   }
5   when SPRING, SUMMER {
6       System.debug('sandals');
7   }
8   when else {
9       System.debug('none of the above');
10   }
11}

Apex Developer Guide

Switch Statements

When Blocks

When Else Block

Examples with Literals

Example with sObjects

Example with Enums