The relationship between PHP regular matching and file encoding

Although most experts think that it will affect the efficiency of the program, but do data collection, but it is difficult to avoid the use of regular, strong regular expression used very comfortable, but in the match Chinese, will appear, clearly the regular expression is not a problem, the character data contained in accordance with the regular expression of data, can be caught, at this time, It's time to stop and see if your matching data is encoded in the same format as your PHP script file. This is because we have a number of Chinese and coding methods, such as: Gbk,utf-8, when your php script file is GBK, and read the need to match the data encoding is UTF-8, they will not return the results you want (no area).