判斷數組對象里的屬性值是否重復

for (var i = 0; i < arr.length - 1; i++) {
            for (var j = i + 1; j < arr.length; j++) {
              if (arr[i].deptName === arr[j].deptName) {
                this.$showWarningMsg('事業部重名了，請重新輸入')
                this.loading = false
                return false
              }
            }
          }