How can I use the Apex utility class for data manipulation, string parsing, and JSON sterilization?

 In the context of Salesforce, here is the example given of how you can use the Apex utility class for operations such as data manipulation, string parsing, or JSON sterilization across multiple apex classes:-

Create a utility class

You can start by creating the utility class with static methods for common operations. For instance, let us consider a method for date formatting and JSON serialization:-

Public class MyUtilityClass {
    // Method to format a date into a specified format
    Public static String formatDate(Date inputDate, String formatString) {
        Return inputDate.format(formatString);
    }
    // Method to serialize an object to JSON format
    Public static String serializeToJson(Object obj) {
        Return JSON.serialize(obj);
    }
}
Using the utility class
Now you can use the utility apex class method in other apex classes throughout your salesforce application:-
@isTest
Public class OpportunityUpdateTriggerTest {
    @isTest static void testOpportunityUpdateTrigger() {
        // Create test Opportunity record
        Opportunity testOpp = new Opportunity(Name=’Test Opportunity’, StageName=’Closed Won’, Amount=1000);
        Insert testOpp;
        // Verify trigger logic
        testOpp = [SELECT Id, Amount FROM Opportunity WHERE Id = :testOpp.Id];
        System.assertEquals(1100, testOpp.Amount, ‘Amount should be updated for Closed Won Opportunity’);
        // Create JSON data for testing utility class
        Map testData = new Map{
            ‘key1’ => ‘value1’,
            ‘key2’ => 123,
            ‘key3’ => true
        };
        String jsonData = MyUtilityClass.serializeToJson(testData);
        System.assertNotEquals(‘’, jsonData, ‘JSON serialization should not be empty’);
    }
}