MyTestClass.cls

@isTest
public class MyTestClass {
    static testMethod void testMyMethod() {
        // BAD PRACTICE: Hard-coding test data
        Account a = new Account(Name='Test Account', Industry='Technology');
        insert a;
        System.assertEquals('Test Account', a.Name);
        System.assertEquals('Technology', a.Industry);
        
        // GOOD PRACTICE: Using variables for test data
        String accountName = 'Test Account 2';
        String industry = 'Finance';
        Account b = new Account(Name=accountName, Industry=industry);
        insert b;
        System.assertEquals(accountName, b.Name);
        System.assertEquals(industry, b.Industry);
    }
}