Rotate a string N times in PHP

Question

I'm looking for a way to rotate a string to the left N times. Here are some examples:

Let the string be abcdef

• if I rotate it 1 time I want bcdefa
• if I rotate it 2 time I want cdefab
• if I rotate it 3 time I want defabc
• .
• .
• If I rotate the string its string length times, I should get back the original string.

Answer 1

 $rotated = substr($str, $n) . substr($str, 0, $n);