Apex Multiline Strings: Real-World Use Cases in Salesforce

 

No more string concatenation or \n hacks — write clean, readable text blocks directly in Apex

If you've ever built a REST callout payload in Apex, you know how messy it gets. A dozen concatenated strings, \n characters everywhere, and a class you had to create just to serialize JSON that had a field named currency. Summer '26 finally fixes this with multiline string templates — using the ''' token.

What Are Apex Multiline Strings?

According to the official Summer '26 release notes, you can now construct strings over multiple lines in Apex using triple single quotes ''' to open and close the block — similar to how you define a multiline comment with /* and */.

Summer '26 also introduces string templates — the ability to pass a Map of values to populate ${variable} placeholders inside a multiline string using the .template() method.

Before vs. After

Here's what building a REST callout payload looked like before Summer '26:

Apex

// Painful string concatenation
String body = '{' +
    '"currency": "USD",' +
    '"amount": 1500,' +
    '"description": "Annual subscription renewal"' +
'}';

// Or even worse — using \n on a single line
String body2 = '{\n"currency": "USD",\n"amount": 1500\n}';

Here's the same thing in Summer '26:

Apex

String body = '''
{
    "currency": "USD",
    "amount": 1500,
    "description": "Annual subscription renewal"
}
''';

Clean, readable, and no concatenation. Exactly what it looks like in the actual payload.

String Templates with .template()

Beyond static text blocks, you can use ${variableName} placeholders inside a multiline string and pass in a Map of values using the .template() method. According to the SalesforceBen Summer '26 developer breakdown:

Apex — string template with .template()

String message = '''
Hello ${firstName},

Your order was dispatched on ${dispatchDate}.
Your tracking reference is ${trackingRef}.

Thank you for your order.
'''.template(
    new Map<String, Object>{
        'firstName'   => 'Kapil',
        'dispatchDate' => Date.today(),
        'trackingRef'  => 'TRK-20260510'
    }
);

Real-World Use Cases

1. REST Callout Payloads with Reserved Words

This is the use case explicitly called out in the official release notes. When a JSON payload needs a field named after an Apex reserved word — like currency, type, or class — you couldn't serialize a class with those property names. Multiline strings solve this completely:

Apex — REST payload with reserved word field names

public String buildPaymentPayload(Decimal amount, String currencyCode) {
    return '''
    {
        "currency": "${currency}",
        "amount": ${amount},
        "type": "charge",
        "class": "standard"
    }
    '''.template(
        new Map<String, Object>{
            'currency' => currencyCode,
            'amount'   => amount
        }
    );
}

2. Email Body Templates

Sending formatted emails from Apex without Visualforce email templates just got much cleaner:

Apex — email body with multiline template

public static void sendWelcomeEmail(Contact c) {
    String body = '''
Dear ${name},

Welcome to Onco Global. Your patient portal is now active.

Portal URL: ${portalUrl}
Your Patient ID: ${patientId}

If you have any questions, please contact your care team.

Regards,
Onco Global Care Team
'''.template(
        new Map<String, Object>{
            'name'      => c.FirstName,
            'portalUrl' => 'https://portal.oncoglobal.com',
            'patientId' => c.MedicalRecordNumber__c
        }
    );

    Messaging.SingleEmailMessage email = new Messaging.SingleEmailMessage();
    email.setPlainTextBody(body);
    email.setToAddresses(new List<String>{ c.Email });
    Messaging.sendEmail(new List<Messaging.SingleEmailMessage>{ email });
}

3. Dynamic SOQL Strings

Multiline strings also make long dynamic SOQL queries far easier to read and maintain:

Apex — readable dynamic SOQL

String query = '''
    SELECT Id, Name, StageName, CloseDate,
           Account.Name, Owner.Name
    FROM Opportunity
    WHERE StageName = 'Closed Won'
    AND CloseDate = THIS_QUARTER
    ORDER BY CloseDate DESC
''';

List<Opportunity> opps = Database.query(query);

Summary & Key Takeaways

🚀 Summer '26 | Apex Multiline Strings — Quick Reference

• Define multiline strings using triple single quotes: ''' open and ''' close
• Use ${variableName} placeholders with .template(Map) for dynamic values
• Best for: REST payloads with reserved-word field names, email body templates, readable dynamic SOQL
• Requires API version 67.0+ — update your .cls-meta.xml before deploying
• Leading whitespace is preserved — use String.stripIndent() if needed
• Not a full replacement for JSON.serialize() — use both where appropriate

This is one of those features that doesn't sound groundbreaking until you're the one maintaining a class full of string concatenation at midnight. Multiline strings won't change how Apex works — but they will change how readable it is, and that matters a lot over time.

📄 Sources: Apex Multiline String Templates — Summer '26 Release Notes  

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