How to Create and Populate Dynamic String Arrays in Apex for Salesforce Trailhead Projects?

Question

I am developing a basic Apex class for a new module in the Salesforce Trailhead program for developers. My objective is as follows:

Construct an Apex class named ‘StringArrayTest’ that generates a list (or array) of strings formatted as ‘Test 0’, ‘Test 1’, and so on. The size of this list is to be determined by a numeric parameter.

Key requirements for the class are:

• The class, ‘StringArrayTest’, should be public.
• It should include a public static method named ‘generateStringArray’.
• This method, ‘generateStringArray’, needs to output a list (or array) of strings, where each string follows the pattern ‘Test n’, with ‘n’ representing the string’s position in the list. The total count of strings in the list is controlled by an integer parameter passed to ‘generateStringArray’.

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Solution:

To begin with, when initializing a List in Apex, you don’t have to specify the initial capacity using an integer. Avoid setting the list’s size upon creation like this:

// Initializing the list without specifying size
String[] myArray = new List<String>();

Additionally, your loop’s logic needs adjustment. Upon initialization, ‘myArray’ will have a size of 0. Modify your loop to correctly iterate through the desired length:

for(Integer i = 0; i < length; i++) {
   // Your code here
}

Within the loop, you’ll be filling the list with strings, utilizing the loop index ‘i’ for numbering:

// Adding elements to the list
myArray.add('Test ' + i);

// Logging each element for debug purposes
System.debug(myArray[i]);

To ensure the method can return your list, its return type should be altered from void. Adjust the method’s signature to:

public static String[] generateStringArray(Integer length)

Then, simply return the populated list at the method’s end:

return myArray;

Combining these elements, the complete class definition should look like this:

public class StringArrayTest {
    // Define the public method
    public static String[] generateStringArray(Integer length) {
        // List initialization
        String[] myArray = new List<String>();

        // Loop to populate the list
        for(Integer i = 0; i < length; i++) {
            // Adding formatted strings to the list
            myArray.add('Test ' + i);

            // Debug log for each element
            System.debug(myArray[i]);
        } // Loop ends

        // Return the fully populated list
        return myArray;
    } // Method ends
} // Class ends

This approach ensures that the Apex class meets the outlined requirements and functions correctly within Salesforce’s development environment.”

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