/**
* Constructs a {@code StringJoiner} with no characters in it using copies
* of the supplied {@code prefix}, {@code delimiter} and {@code suffix}.
* If no characters are added to the {@code StringJoiner} and methods
* accessing the string value of it are invoked, it will return the
* {@code prefix + suffix} (or properties thereof) in the result, unless
* {@code setEmptyValue} has first been called.
*
* @param string $delimiter
* the sequence of characters to be used between each
* element added to the {@code StringJoiner}
* @param string $prefix
* the sequence of characters to be used at the beginning
* @param string $suffix
* the sequence of characters to be used at the end
* @throws NullPointerException if {@code prefix}, {@code delimiter}, or
* {@code suffix} is {@code null}
*/
public function __construct($delimiter, $prefix = null, $suffix = null)
{
Objects::requireNonNull($delimiter, "The delimiter must not be null");
if (null === $prefix xor null === $suffix) {
Objects::requireNonNull($prefix, "The prefix must not be null");
Objects::requireNonNull($suffix, "The suffix must not be null");
}
$this->prefix = new String($prefix);
$this->delimiter = new String($delimiter);
$this->suffix = new String($suffix);
$this->emptyValue = $this->prefix->concat($this->suffix);
}
public function testConcat()
{
$this->assertEquals(self::STRING_VALUE . '0', $this->string->concat(new String('0')));
}
