实验1

package com.shiyanlou;

public class TestEx301 {

public static void main(String[] args) {

// TODO Auto-generated method stub

double a = Math.random();

double b = Math.random();

System.out.println(Math.pow(a, 8));

System.out.println(Math.round(b));

System.out.println(Math.log(Math.pow(Math.E, 5)));

double d = 60.0, r = Math.PI / 4;

System.out.println(Math.toRadians(d));

System.out.println(Math.toDegrees(r));

}

｝

实验2

package com.shiyanlou;

public class TestEx302 {

public static void main(String[] args) {

StringBuffer str = new StringBuffer("19880117010");

str.insert(0, "0532-");

str.setCharAt(7, '8');

str.setCharAt(str.length() - 1, '7');

System.out.println(str);

}

}

实验三

package com.shiyanlou;

public class TestEx303 {

public static void main(String[] args) {

// TODO Auto-generated method stub

String a[] = { "desk", "apple", "Applet", "hotgirl", "coolboy" };

for (int i = 0; i < a.length - 1; i++) {

for (int j = i + 1; j < a.length; j++) {

if (a[j].compareTo(a[i]) < 0) {

String temp = a[i];

a[i] = a[j];

a[j] = temp;

}

}

}

for(int i=0;i

System.out.println(a[i]);

}

}

}

实验4

class A{}

class B extends A{}

public class TestEx304a{

public static void main(String args[]){

A a=new A();

B b=(B)a;

}

public class TestEx304b{

public static void main(String arg[]){

int a[]=new int [10];

for (int i=0 ;i<=10;i++){a[i]=0;}

}

}

public class TestEx304c{

public static void main(String arg[]){

int s=100;

for (int i=-3;i<5;i++){s=s/i;}

}

}

public class TestEx304d{

public static void main(String args[]){

String s1=new String("aaaa bbbb cccc");

System.out.println(s1);

String s2;

s2=s1.substring(30);

System.out.println(s2);

}

}