How does php convert UTF-8 encoding to gbk simplified?

How does php convert UTF-8 encoding to gbk simplified? As the question. I will convert the traditional big encoding to simplified ones.

Reply to discussion (solution)

Switch to big5 first.

Simple and traditional conversion requires a code table. the encoding is converted to mb or iconv.

I found the solution temporarily. Convert UTF-8 to big5 encoding, and then replace big5 with gbk. The effect is satisfactory.

Switch to big5 first.

Simple and traditional conversion requires a code table. the encoding is converted to mb or iconv.

I did the same.