字符串常量演示Demo

public class StringDemo {

public static void main(String[] args) {
// TODO Auto-generated method stub

String str = "abc";
String str2 = "abc";
//System.out.println(str==str2);  //true
//System.out.println(str.equals(str2)); //true

String str3 = new String("abc");
String str4 = "abc";
//System.out.println(str3==str4);  //false
//System.out.println(str3.equals(str4)); // true

String str5 = "ab"+"c";
String str6 = "a"+"bc";
//System.out.println(str5==str6);  // true
//System.out.println(str5.equals(str6)); //true

String str7 = "ab";
String str8 = str7+"c";
String str9 = "ab"+"c";

//System.out.println(str8.equals(str9)); // true
//System.out.println(str8 == str9); // false  --str8 是运行时的变量，而str9是字符串常量表达式

String str10 = "abc";
String str11 = new String("abc");
String str12 = str11.intern();
System.out.println(str10 == str11); //false
System.out.println(str10.equals(str11)); //true
System.out.println(str11.equals(str12)); //true

}

}

转载于:https://www.cnblogs.com/childhooding/p/4642614.html