java中String类中的replace方法

package stringTest;

public class StringDemo2 {
public static void main(String[] args) {
String s = "acvbb";
String s1 = new String("acvbb");

String s2 = s.replace("a", "X");
String s3 = s1.replace("a", "X");

/**
* String类中的replace方法表示字符串替换，不改变原始的字符串；
* 该方法返回替换后的字符串
* */
System.out.println("s = " + s);  //s = acvbb
System.out.println("s2 = " + s2); //s2 = Xcvbb

System.out.println("s1 = " + s1); //s1 = acvbb
System.out.println("s3 = " + s3); //s3 = Xcvbb
}
}

s = acvbb
s2 = Xcvbb
s1 = acvbb
s3 = Xcvbb