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Java基础
package liping.com; import java.util.Date; import java.io.*; public class HelloWorld { public String name; public String sex; public int age; private double salary; public void sleep(){ age = age +25; System.out.println("人类啥都吃"); System.out.println("你的年纪是:"+age); } public void setNmae(String name1){ name = name1; } public void setSalary(double salary1){ salary = salary1; } public void printInf(){ System.out.println("名字:"+name); System.out.println("薪水:"+salary); } public static int max(int num1,int num2){ int result; if(num1 > num2){ result = num1; }else{ result = num2; } return result; } public static void main(String[] args) throws IOException { //类和对象 HelloWorld xiaoming=new HelloWorld(); xiaoming.setNmae("小明"); xiaoming.setSalary(10000); xiaoming.sleep(); xiaoming.printInf(); int larger = max(888,999); System.out.println("比较大的一个值是:"+larger); //基本数据类型的基本情况打印 System.out.println("基本类型:byte 二进制位数:" + Byte.SIZE); System.out.println("包装类:java.lpng,integer"); System.out.println("最小值:interger.Min_value="http://www.mamicode.com/+Byte.MIN_VALUE); System.out.println("最大值:interger.Max_value="http://www.mamicode.com/+Byte.MAX_VALUE); //数据类型的强制转换 char c1 = ‘a‘; int i1 =c1; System.out.println("char类型转换为int后的值:"+i1); char c2 = ‘A‘; int i2 = c2 +1; System.out.println("char类型转化为后的值:"+i2); byte b = (byte)c1; System.out.println("char强转之后的值:"+b); //位运算符 int a3 = 60; /* 60 = 0011 1100 */ int b3 = 13; /* 13 = 0000 1101 */ int c3 = 0; c3 = a3 & b3;/* 12 = 0000 1100 */// 如果相对应位都是1,则结果为1,否则为0 System.out.println("a3 & b3 = " +c3); c3 = a3 | b3;/* 61 = 0011 1101 */// 如果相对应位都是0,则结果为0,否则为1 System.out.println("a3 | b3 = " + c3 ); c3 = a3 ^ b3;/* 49 = 0011 0001 */// 如果相对应位值相同,则结果为0,否则为1 System.out.println("a3 ^ b3 = " + c3 ); c3 = ~a3; /*-61 = 1100 0011 */// 按位补运算符翻转操作数的每一位,即0变成1,1变成0。 System.out.println("~a3 = " + c3 ); c3 = a3 << 2; /* 240 = 1111 0000 *///按位左移运算符。左操作数按位左移右操作数指定的位数。 System.out.println("a3 << 2 = " + c3 ); c3 = a3 >> 2; /* 15 = 1111 */// 按位右移运算符。左操作数按位右移右操作数指定的位数。 System.out.println("a3 >> 2 = " + c3 ); c3 = a3 >>> 2; /* 15 = 0000 1111 *///按位右移补零操作符。左操作数的值按右操作数指定的位数右移,移动得到的空位以零填充 System.out.println("a3 >>> 2 = " + c3 ); //循环 int x = 10; while (x<20){ System.out.println("Volue of x :" + x); x++; System.out.println("\n"); } do { System.out.println("Volue of x :" + x); x++; }while(x < 20); for(int x1 = 10; x1<20; x1++){ System.out.println("value of x1:"+x1); System.out.println("\n"); } String [] names = {"科比","詹姆斯","库里","杜兰特"}; for( String name : names ) { if(name.equals("库里")){ break; } System.out.print( name ); System.out.print(",\n"); } //分支结构 int x2 = 888; if(x2 == 10){ System.out.println("value is 10"); }else if(x2 == 50){ System.out.println( "value is 50"); }else{ System.out.println("我也不知道x2的值是多少"); } char grade = ‘C‘; switch(grade) { case ‘A‘ : System.out.println("优秀"); break; case ‘B‘ : System.out.println("良好"); break; case ‘C‘ : System.out.println("中等"); break; case ‘D‘ : System.out.println("及格"); case ‘F‘ : System.out.println("你需要再努力努力"); break; default : System.out.println("未知等级"); } System.out.println("你的等级是 " + grade); //Java Math类 System.out.println("90度的正玄值:"+Math.sin(Math.PI/2)); System.out.println("0度的余玄值:"+Math.cos(0)); System.out.println("60度的正切值:"+Math.tan(Math.PI/3)); System.out.println("1的反切值:"+Math.atan(1)); System.out.println("n/2的角度值:"+Math.toDegrees(Math.PI/2)); System.out.println(Math.PI); //Java StringBuffer 和 StringBuilder 类 StringBuffer sBuffer = new StringBuffer("菜鸟教程官网:"); sBuffer.append("www.runoob.com"); System.out.println(sBuffer); //数组 double[] myList = {1.9, 2.9, 3.4, 3.5}; // 打印所有数组元素 for (int i = 0; i < myList.length; i++) { System.out.println(myList[i] + " "); } // 计算所有元素的总和 double total = 0; for (int i = 0; i < myList.length; i++) { total += myList[i]; } System.out.println("Total is " + total); // 查找最大元素 double max = myList[0]; for (int i = 1; i < myList.length; i++) { if (myList[i] > max) max = myList[i]; } System.out.println("Max is " + max); Date date = new Date(); System.out.println(date.toString()); String str = String.format("Current Date/Time : %tc", date ); System.out.println(str); System.out.printf("%s %tB %<te, %<tY", "Due date:", date); char scanf; BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); System.out.println("s输入字符,按下‘q’键退出"); do{ scanf = (char) br.read(); System.out.println(scanf); }while(scanf != ‘q‘); } }
Java基础
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