1。package com.itheima01; public class HelloWorld { public static void main(String[] args){ int a=1; int b=2; int c; c=a; a=b; b=c; System.out.println("a的值是"+a+"b的值是"+b); } } 2.package com.itheima01;66666 public class HelloWorld { public static void main(String[] args){ int a=909; int b=a%10; int c=a%100/10; int d=a/100; int sum=b+c+d; System.out.println(sum); } } 3.package com.itheima01; public class HelloWorld { public static void main(String[] args){ double a=95;//华氏温度 double b=36;//摄氏温度 double c=(a-32)*5/9; double d=b*9/5+32; System.out.println(c); System.out.println(d); } } 4.package com.itheima01; public class HelloWorld { public static void main(String[] args){ char e='E'; System.out.println((char)(e+32)); } }