Determine the character length, distinguish between Chinese and English (two characters for Chinese and one character for English)

const RegCn = /[\u4e00-\u9fa5]/g;
                 let value = '你好啊aa';
                 value = value.replace(RegCn, 'aa');
         console.info(value.length);//8

let RegCn = /[\u4e00-\u9fa5]/g;
                 let value = 'aA';
                 value = value.replace(RegCn, 'aa');
         console.info(value.length);//2

let RegCn = /[\u4e00-\u9fa5]/g;
                 let value = '啦';
                 value = value.replace(RegCn, 'aa');
         console.info(value.length);//2