代碼如下：'z/yy'.replace(/\/(y|z)|y|z/g,function(name,index){console.log(index,name.length);returnname=='y'||name=='z'?'a':name;});正確輸出：a/ya'z/yy'.replace(/\/(y|z)|\1/g,function(name,index){console.log(index,name.length);returnname=='y'||name=='z'?'a':name;});錯誤輸出：z/yy請問為什么呢？