小编Min*_*ser的帖子

是否有执行的性能开销sb.indexOf(c + "") ，其中c是类型Character还是char和sb为StringBuilder对象？

我想知道是否有更好的方法来实现createEmployee(),它使用字典或其他方式快速查找所请求的类型而不是if-else块.

function Clerk( options ) {
            this.hourRate = options.hourRate || 20;
            this.firstName = options.firstName || "no first name";
            this.lastName = options.lastName || "no last name";
            this.id = options.id || "-9999999999";
        }

        function Manager( options) {
            this.hourRate = options.hourRate || 200;
            this.firstName = options.firstName || "no first name";
            this.lastName = options.lastName || "no last name";
            this.id = options.id || "-9999999999";
            this.yearBonus = options.yearBonus || "200000";
        }

        function Teacher( options) {
            this.hourRate = options.hourRate || 100;
            this.firstName = options.firstName || "no first …