package Demo_1_22_String;

public class StringConcat {
    public static void main(String[] args) {
        String strA = "www.sss.cn";
        String strB = "www.".concat("sss.cn");

        System.out.println(strB);
        System.out.println(strA == strB); //false 并没有实现静态的定义

        String strC = "www.".concat("sss.cn").intern(); //入池操作
        System.out.println(strA == strC);   // ture

        System.out.println("==============================");
        // isEmpty():判断是否为空
        String strD = "";
        System.out.println(strD.isEmpty());     // ture
        System.out.println("sss".isEmpty());    // false

    }
}