Is the SWITCH and CASE statement supported in APEX in Salesforce?

Question

Instead of this basic structure with IF / THEN / ELSEIF / ELSE

int month = 8;
String monthString;
if (month == 1) {
    monthString = "January";
} else if (month == 2) {
    monthString = "February";
}
...  // and so on

it would be nice to have

    int month = 8;
    String monthString;
    switch (month) {
        case 1:  monthString = "January";
                 break;
        case 2:  monthString = "February";
                 break;

        ..... // and so on

        case 12: monthString = "December";
                 break;
        default: monthString = "Invalid month";
                 break;
    }

This would increase readability and make it easier to debug due to clarity of intent.

Answer 1

switch statement support is coming to Apex in the Summer '18 release.

From the TrailheadX 2018 session Switching It Up with Apex:

Initially it will support Enums, String, Integer, and Long

Answer 2

Meanwhile SFDC is providing native engine, as work-around you can use small utility 'framework' as switch-case object-oriented 'statement':

Switch-Case Utility

Example usage:

public with sharing class SwitchCaseExample {

    public String result {get; set;}

    public static final String MSG_FROM_ACTION_1 = 'invoke action 1';
    public static final String MSG_FROM_ACTION_2 = 'invoke action 2';
    public static final String MSG_FROM_ACTION_3 = 'invoke action 3';
    public static final String MSG_FROM_ACTION_4 = 'invoke action 4';

    public void testSwitchCase(String value) {

        SwitchCaseHelper sch = new SwitchCaseHelper();  

        sch.switch(value)
            .case('value1', new Action1(this), SwitchCaseHelper.PUT_BREAK)
            .case('value2', new Action2(this), SwitchCaseHelper.PUT_CONTINUE)
            .case('value3', new Action3(this), SwitchCaseHelper.PUT_BREAK)
            .default(new Action4(this));
    }


    private class Action1 implements ActionContainer {

        private SwitchCaseExample outerCtx;

        public Action1(SwitchCaseExample outerCtx) {

            this.outerCtx = outerCtx;
        }

        public String doAction() {

            outerCtx.result = MSG_FROM_ACTION_1;
            return null; 
        }
    }

    private class Action2 implements ActionContainer {

        private SwitchCaseExample outerCtx;

        public Action2(SwitchCaseExample outerCtx) {

            this.outerCtx = outerCtx;
        }

        public String doAction() {

            outerCtx.result = MSG_FROM_ACTION_2;
            return null; 
        }
    }

    private class Action3 implements ActionContainer {

        private SwitchCaseExample outerCtx;

        public Action3(SwitchCaseExample outerCtx) {

            this.outerCtx = outerCtx;
        }

        public String doAction() {

            outerCtx.result = MSG_FROM_ACTION_3;
            return null; 
        }
    }

    private class Action4 implements ActionContainer {

        private SwitchCaseExample outerCtx;

        public Action4(SwitchCaseExample outerCtx) {

            this.outerCtx = outerCtx;
        }

        public String doAction() {

            outerCtx.result = MSG_FROM_ACTION_4;
            return null; 
        }
    }

}

Interface:

public interface ActionContainer {

    String doAction();

}

And switch-case logic implementation

public with sharing class SwitchCaseHelper {

    public static final Boolean PUT_BREAK = true;
    public static final Boolean PUT_CONTINUE = false;

    public class SwitchCaseException extends Exception {}

    public static final String EXCEPTION_MESSAGE = 'Switch-Case construction must have one (and only one) "switch" statement';

    @TestVisible
    private Object switchOperand;

    @TestVisible
    private Boolean isCaseAfterBreakStatement;

    @TestVisible
    private Boolean isPreviousSwitch;

    public SwitchCaseHelper() {

        isCaseAfterBreakStatement = false;
    }

    public SwitchCaseHelper switch(Object switchOperand) {

        if (isPreviousSwitch != null) {
            throw new SwitchCaseException(EXCEPTION_MESSAGE);
        }
        isPreviousSwitch = true;
        this.switchOperand = switchOperand;
        return this;
    }

    public SwitchCaseHelper case(Object caseOperand, ActionContainer container, Boolean hasBreak) {

        if (isPreviousSwitch == null) {
            throw new SwitchCaseException(EXCEPTION_MESSAGE);
        }

        if (isPreviousSwitch) {
            isPreviousSwitch = false;
        }

        if (isCaseAfterBreakStatement) {
            return this;
        }

        if (switchOperand.equals(caseOperand)) {
            container.doAction();
            isCaseAfterBreakStatement = hasBreak;
        }

        return this;
    }

    public SwitchCaseHelper default(ActionContainer container) {

        if (isPreviousSwitch == null) {
            throw new SwitchCaseException(EXCEPTION_MESSAGE);
        }

        if (!isCaseAfterBreakStatement) {
            container.doAction();
        }
        return this;
    }
}