package com.daxing_01;

public class StringBuiderDemo02 {
    public static void main(String[] args) {
        //StringBuilder转化为String
        StringBuilder st = new StringBuilder();
        st.append("hello");
        String s = st.toString();
        System.out.println(s);

        //String转化为StringBuilder
        String r="hello";
        StringBuilder sb = new StringBuilder(r);
        System.out.println(sb);
    }
}

输出：

hello
hello

Process finished with exit code 0