submitWpsStringInputs.DELIMITER may exist but you may want to do the following:

```
if (submitWpsStringInputs.hasOwnProperty('DELIMITER') &&
    submitWpsStringInputs.DELIMITER &&
    Object.prototype.toString.call(submitWpsStringInputs.DELIMITER) === "[object Array]" &&
    submitWpsStringInputs.DELIMITER.length > 0) {
    ...
}
```