{
public static void main(String[] args)
{
//关系运算符号
System.out.println(method1()&method2()&method3());
System.out.println(method1()|method2()|method3());
System.out.println(method1()&&method2()&&method3());
System.out.println(method1()||method2()||method3());
System.out.println("----------------------------------------------------");
//位运算的例子,交换两数
int a = 10;
int b = 20;
//方法一
a = a ^ b;
b = a ^ b;
a = a ^ b;
//方法二
a = a + b;
b = a - b;
a = a - b;
//方法三
b = a + (a = b) * 0;
System.out.println(a + " " + b);
System.out.println(" " + a + b);
System.out.println(a + b + " ");
System.out.println("----------------------------------------------------");
//"+ _ * /"
a = a + b;
System.out.println(a);
a = a - b;
System.out.println(a);
a = a * b;
System.out.println(a);
a = a / b;
System.out.println(a);
a = a % b;
System.out.println(a);
a++;
System.out.println(a);
++a;
System.out.println(a);
a--;
System.out.println(a);
--a;
System.out.println(a);
System.out.println("----------------------------------------------------");
//计算机运算速度最快的是位移操作
System.out.println(32 << 3);
System.out.println(32 >> 3);
System.out.println(32 >>> 3);
System.out.println("----------------------------------------------------");
//前者比后者执行速度快
a += b;
a = a + b;
System.out.println(a + " " + b);
System.out.println("----------------------------------------------------");
//if语句
int c = 40;
System.out.println("c == 40");
if(c > 60) {
System.out.println("*******");
} else if(c < 60) {
System.out.println("-------");
} else {
System.out.println("========");
}
System.out.println("----------------------------------------------------");
//switch break;语句
int d = 'a';
switch(d) {
case 97: System.out.println("1111111111");
break;
case 80: System.out.println("2222222222");
break;
default: System.out.println("3333333333");
}
System.out.println("----------------------------------------------------");
//for循环
//写法1
for(int i = 1; i <= 20; i++) {
System.out.println(i);
}
//写法2
int x = 1;
for(; x <= 10;) {
System.out.println(x);
x++;
}
System.out.println("----------------------------------------------------");
//while循环
int y = 6;
while(y <= 15) {
System.out.println(y);
y++;
}
System.out.println("----------------------------------------------------");
//do while 循环
int z = 1;
do {
System.out.println(z);
z++;
}
while (z <= 2);
System.out.println(z);
System.out.println("----------------------------------------------------");
//循环嵌套
outer:
for (int i = 1;i <= 5;i++ ){
if (i > 3) {
//System.out.println(i);
break outer;
}
inner:
for(int j = 1; j <= 10; j++) {
System.out.println("i = " + i + " j = " + j);
if(j == 3) {
//break outer;
continue inner;
//berak(所有)是终止循环continue(for/while/do)是省略剩下的循环并开始新的循环
//先执行内循环,然后依次执行外循环;
//用外循环来控制内循环的执行次数
}
}
}
System.out.println("----------------------------------------------------");
}//尾括号
public static boolean method1() {
System.out.println("method1.......");
return true;
}
public static boolean method2() {
System.out.println("method2.......");
return false;
}
public static boolean method3() {
System.out.println("method3.......");
return true;
}
}
class Array
{
public static void main(String[] args)
{
int[] a = {100,20,34,65,43,83,64,27,1,88,53,90,89,67};
for(int i = 0; i < a.length; i++) {
for(int j = 0; j < a.length - i - 1; j++) {
//比较数值的过程
if(a[j] > a[j + 1]) {
// a[j] = a[j] + a[j + 1];
// a[j + 1] = a[j] - a[j + 1];
// a[j] = a[j] - a[j + 1];
a[j + 1] = a[j] + (a[j] = a[j + 1]) * 0;
}
System.out.print(a[j] + " ");
}
System.out.println(a[i]);
}
System.out.println("--------------------------冒泡排序结果如下:");
for (int k = 0;k < a.length ;k++ )
{
System.out.print(a[k] + " ");
}
}//
}
















