StringJoiner 小练习之二

`import java.util.StringJoiner;
public class Demo13{
public static void main(String[] args) {

String[] names = {"Bob", "Alice", "Grace"};

//数组元素间用分隔符"," 打印出来Hello Bob, Alice, Grace !

//这是一个重载构造器，第一个参数表示分隔符，第二个参数表示开头，第三个参数表示结尾

StringJoiner sj = new StringJoiner(", ","Hello "," ！");

for(String name:names){
sj.add(name);
}

System.out.println(sj.toString());

}

}`