vue for each循環出來數組的某一項 再重新合並成一個新數組

 search() {

      request

        .get("/manager")

        .then(res => {

          if (res.code == 20000) {

            this.tableData = res.data.list;

            var categorystr = ''

            var classifystr = ''

            this.tableData.forEach(function(c) {

              categorystr += c.category + ","

              classifystr += c.classify + ","

            });

            categorystr = categorystr.substring(0,categorystr.length-1)

            classifystr = classifystr.substring(0,classifystr.length-1)

            this.categoryList = categorystr.split(",")

            this.classifystr = classifystr.split(",")

            // console.log(str)

            // console.log(this.categoryList)

          }

        })

        .catch(err => {

          console.log(err);

        });