1、String --> int
Integer s1 = Integer.valueOf("123"); System.out.println(s1);//123
2、Integer —> String
Integer x = Integer.valueOf(s1); System.out.println(x);//123
3、Integer —>int自动装箱
Integer i1 = 5;
4、int —>Integer自动拆箱
int i2 = i1;
5、String —> int
int i = Integer.parseInt("100"); System.out.println(i + 1);//101
6、int — String
String s = i + "";//"100"字符串 System.out.println(s + 1);//1001
7、图解
