Optimizing number of IF-Else statements

Question

I need to add IF-ELSE condition in an existing method :

Statement will be like

If (field = X)
    { value = 'Yes'}
else if (field = Y)
    { value = 'No'}
else { value = 'NA' }

Is there any way to optimize the number of if-else statements ?

Answer 1

Not relevant if only a couple of if/else, but if there are many, sometimes creating a map is a good way to go:

private static final Map<String, String> MY_MAP = new Map<String, String>{
        'abc' => '123',
        'def' => '456',
        'ghi' => '789',
        ...
        };

    ....
    String output = MY_MAP.get(input);

This code can be easier to read and understand and also helps performance because the result is a direct map lookup rather than multiple if condition evaluations.

In my company we no longer put curly brackets round single statements that fit easily on the same line as the condition to cut down the visual noise so would code the logic in the question like this:

if (field == X) value = 'Yes';
else if (field == Y) value = 'No';
else value = 'NA';

Answer 2

There's a few things around if statements you should probably consider.

The elephant in the room (in my opinion) is that Apex does not support switch statements.

Given you appear to be updating a value based on another fields value, you may want to consider using clicks, not code. As a rule of thumb, use:

• Process Builder when you have multiple if/then statements
• Workflow when you have a single if/then statement

If you must use Apex, you can use an inline-if statement, otherwise known as a ternary operator as outlined in @salesforceMann's answer which you can test using the below code that will debug "N/A".

String field = 'z';
String result = field == 'x' ? 'Yes' : field == 'y' ? 'No' : 'N/A';
System.debug(result);

Compared with the following:

String field = 'z';
String result;

if (field == 'x') {
    reuslt = 'Yes';
}
else if (field == 'y') {
    result = 'No';
}
else {
    result = 'N/A';
}

System.debug(result);

You can immediately see that you're saving, relatively, a lot of space and you'll save a bit on heap allocation.

Not to steal @salesforceMann's thunder here, but wanted to add a bit more for something this simple.

Answer 3

The Summer '18 (v43.0) release is planned to include native switch statement support in Apex.

In this scenario the minimal code would go from:

if (field == X) {
    value = 'Yes';
} else if (field == Y) {
    value = 'No';
} else {
    value = 'NA';
}

To:

switch on field {
    when 'X' {
        value = 'Yes';
    }
    when 'Y' {
        Value = 'No';
    }
    when else {
        value = 'NA';
    }
}

Note that I had change the variables X and Y to literals in the switch statement. Otherwise you get the error:

'when identifier' is only allowed for switch on enum

Please consider voting for the idea Add support for final variables in switch statement when clauses

---

In this specific case you are unlikely to see any improvement. Especially when compared to a Map based lookup solution. However, there may be more complicated scenarios where a switch statement will make the code easier to read. It might just be a case of moving X and Y into an enum so they could be used directly in the switch conditions.

Answer 4

Yes! Try:

Field == X ? 'Yes' : (Field == Y ? 'No' : 'NA')

Instead of:

if (field = X) { 
    value = 'Yes'
} 
else if (field = Y) { 
    value = 'No'
} else { 
    value = 'NA' 
}

Answer 5

What the others have said about Ternary operators is accurate. They are also a lot faster on compile than if/else statements, somewhere around 30%.

Answer 6

Not much, but is saves you one comparission; assign the default value, then check for your special cases:

value = 'NA'

If (field = X)
    { value = 'Yes'}
else if (field = Y)
    { value = 'No'}

This is clearer, more immediately comprehensible and more maintainable then the terniary operator.

Hope for switch statements in future versions.

Answer 7

Switch Statements is now live in Salesforce (from Summer '18 Release).

Syntax:

switch on expression {
when value1 {       // when block 1
    // code block 1
}   
when value2 {       // when block 2
    // code block 2
}
when value3 {       // when block 3
    // code block 3
}
when else {       // default block, optional
    // code block 4
}
}

Simple Example:

switch on i {
   when 2 {
       System.debug('when block 2');
   }
   when null {
       System.debug('bad integer');
   }
   when else {
       System.debug('default ' + i);
   }
}

Please check Salesforce documentation on Switch for more information.

Answer 8

A drawback of the ternary solution is when the values to be assigned are function results. I don't know about Apex, but in most languages all values that could be assigned are evaluated even if only one of them is used. This is, at best, a performance problem and worse if the functions have any side-effects.