Change fullwidth characters to halfwidth

Question

"合同会社Ｋｎｏｗｌｅｄｇｅ　Ｌｉｂｒａｒｙ" => "合同会社Knowledge Library"

I want to convert only alphanumeric characters in the string to single byte using java script or php

Answer 1

In PHP, use mb_convert_kana to convert "zen-kaku" to "han-kaku".