输入字符串,要求把傻瓜替换为**,我写了运行出来没有结果,求答

Question

```java
public class Demo02 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.println("请输入一个字符串");
        String n1 = sc.next();
        StringBuilder s1 = exchangesb(n1);
        System.out.println(s1);
    }

    public static StringBuilder exchangesb(String n1){

        if("傻瓜".equals(n1)){
            n1.replace("傻瓜","**");
        }
        StringBuilder sb = new StringBuilder(n1);
        return sb;
    }
}

```

Answer 1

16行 replace 不会改变原字符串的值,可改为

n1 = n1.replace("傻瓜","**");