如果输入中的字符串序列包含了数组中的元素，该如何替换？

def replace_elements(input_str, arr, replacement):
    for element in arr:
        input_str = input_str.replace(element, replacement)
    return input_str

input_str = "This is a test string."
arr = ["is", "test"]
replacement = "REPLACED"
result = replace_elements(input_str, arr, replacement)
print(result)

public class StringReplacement {
    public static String replaceElements(String inputStr, String[] arr, String replacement) {
        for (String element : arr) {
            inputStr = inputStr.replace(element, replacement);
        }
        return inputStr;
    }

    public static void main(String[] args) {
        String inputStr = "This is a test string.";
        String[] arr = {"is", "test"};
        String replacement = "REPLACED";
        String result = replaceElements(inputStr, arr, replacement);
        System.out.println(result);
    }
}