标签:str1 new ring enc pack pre 变量 java int
例1:
package com.jike.reference; class Ref1{ int temp = 10; } public class test01 { public static void main(String[] args) { Ref1 r1 =new Ref1(); r1.temp = 20; System.out.println(r1.temp); tell(r1); System.out.println(r1.temp); } public static void tell(Ref1 r2){ r2.temp = 30; } }
输出:
20 30
例2:
package com.jike.reference; public class test02 { public static void main(String[] args) { String str1 = "Hello"; System.out.println(str1); tell(str1); System.out.println(str1); } public static void tell(String str2){ str2="jike"; } }
输出:
Hello Hello
string类型的变量str1不会被改变,str2="jike"会在堆中开辟另一个新的内存地址存放“jike”,原本的str1仍然指向"Hello"。
例3:
package com.jike.reference; class Ref2{ String temp = "hello"; } public class test03 { public static void main(String[] args) { Ref2 r1 = new Ref2(); r1.temp="jike"; System.out.println(r1.temp); tell(r1); System.out.println(r1.temp); } public static void tell(Ref2 r2){ r2.temp="xueyuan"; } }
输出:
jike xueyuan
例1和例3是相同类型的,例2涉及到string类型有些特殊。
标签:str1 new ring enc pack pre 变量 java int
原文地址:https://www.cnblogs.com/zhhy236400/p/10438307.html