StringBuilder和String的相互转换_idea莫名其妙的 stringbuilder自动变成 string

package MyString;
/*
    StringBuilder和String的相互转换：转换后方便其转换后的调用方法
    StringBuilder -- String
            public String toString():通过sb.toString()既可以实现把StringBuilder转化为String
    String -- StringBuilder
            StringBuilder(String str):通过构造方法StringBuilder sb = new StringBuilder(s);实现转化
 */
public class StringBuilderToString {
    public static void main(String[] args) {
        //StringBuilder -- String
        StringBuilder sb = new StringBuilder();
        sb.append("hello").append(123);
        String s = sb.toString();
        System.out.println("s:"+s);

        //String -- StringBuilder
        String s1 = "超人强777";
        StringBuilder sb1 = new StringBuilder(s1);
        System.out.println("sb1:"+sb1);

    }
}
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