/[\u0600-\u06ff]|[\u0750-\u077f]|[\ufb50-\ufbc1]|[\ufbd3-\ufd3f]|[\ufd50-\ufd8f]|[\ufd92-\ufdc7]|[\ufe70-\ufefc]|[\uFDF0-\uFDFD]/
Arabic (0600—06FF, 225 characters)
Arabic Supplement (0750—077F, 48 characters)
Arabic Extended-A (08A0—08FF, 39 characters)
Arabic Presentation Forms-A (FB50—FDFF, 608 characters)
Arabic Presentation Forms-B (FE70—FEFF, 140 characters)
Rumi Numeral Symbols (10E60—10E7F, 31 characters)
Arabic Mathematical Alphabetic Symbols (1EE00—1EEFF, 143 characters)
For more info check this Wiki link to see arabic letters in Unicode:
https://en.wikipedia.org/wiki/Arabic_(Unicode_block)
http://stackoverflow.com/questions/11323596/regular-expression-for-arabic-language