/**
 * Concatenates two strings and returns the result.
 *
 * The input strings may be null, in which case the function should treat them as empty strings.
 *
 * Example:
 * concatenateStrings("Hello", "World") should return "HelloWorld"
 * concatenateStrings(null, "World") should return "World"
 * concatenateStrings("Hello", null) should return "Hello"
 * concatenateStrings(null, null) should return ""
 */
fun concatenateStrings(string1: String?, string2: String?): String {

    val str1 = string1 ?: ""
    val str2 = string2 ?: ""
    
    // Concatenate the two strings
    val result = str1 + str2
    
    return result
}
/**
 * Concatenates two strings and returns the result.
 *
 * The input strings may be null, in which case the function should treat them as empty strings.
 *
 * Example:
 * concatenateStrings("Hello", "World") should return "HelloWorld"
 * concatenateStrings(null, "World") should return "World"
 * concatenateStrings("Hello", null) should return "Hello"
 * concatenateStrings(null, null) should return ""
 */
fun concatenateStrings(string1: String?, string2: String?): String {
/**
 * Concatenates two strings and returns the result.
 *
 * The input strings may be null, in which case the function should treat them as empty strings.
 *
 * Example:
 * concatenateStrings("Hello", "World") should return "HelloWorld"
 * concatenateStrings(null, "World") should return "World"
 * concatenateStrings("Hello", null) should return "Hello"
 * concatenateStrings(null, null) should return ""
 */
fun concatenateStrings(string1: String?, string2: String?): String {

    val str1 = string1 ?: ""
    val str2 = string2 ?: ""
    
    // Concatenate the two strings
    val result = str1 + str2
    
    return result
}