JAVA语言中开方求根等公式方法有总结一块的的没?

刚才抽了，B~~~~~~~~
一眼看着D以为没有了~~
const是Java的一个保留关键字，没有使用。
sizeof真的是C/C++的，Java里没有~~
（const敲进eclipse里是会变色的，虽然点编译会出错）

import java.util.Scanner;
public class TestObject {
/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
Scanner in = new Scanner(System.in);
System.out.println("请输入第一个坐标点：");
int x1 = in.nextInt();
int y1 = in.nextInt();
System.out.println("请输入第二个坐标点：");
int x2 = in.nextInt();
int y2 = in.nextInt();
int distance = (int) Math.sqrt(Math.abs((x1 - x2)*(x1 - x2))+Math.abs((y1 - y2)*(y1 - y2)));
System.out.println("两点间距离是："+distance);
}
}

你好好看看Math相关的api

出这个题的人有毛病，java是先将.java编译成.class,然后这些字节码又需要JVM的解释。。。考试的话还是勉强选C吧，根本没有半编译型这种说法，只是Java比较特别而已。

其实这种逻辑运算的,提现不错Java的面向对象的概念的,你直接写逻辑语句就好,首先判断等边,即if(a==b==c) System.out.print("该三角形是等边三角形");
这样写下去就好了.希望采纳

删除不好做，因为你是一个文件内容的删除。可以用字符串数组来保存每一行的给每个表的列名都采用统一的前缀，那么在编写SQL表达式的时候会得到大大的简化

这题目如果能增加一个类的话会高效很多.如果非要在这个框框里面,代码麻烦 效率低下呢.
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.Iterator;
import java.util.List;
import java.util.Set;
import java.util.TreeSet;
public class Article {
//保存文章的内容
String content;
//保存分割后的单词集合
String[] rawWords;
//保存统计后的单词集合
String[] words;
//保存单词对应的词频
int[] wordFreqs;
//构造函数,输入文章内容
//提高部分：从文件中读取
public Article() {
content = "kolya is one of the richest films i've seen in some time . zdenek sverak plays a confirmed old bachelor ( who's likely to remain so ) , who finds his life as a czech cellist increasingly impacted by the five-year old boy that he's taking care of . though it ends rather abruptly-- and i'm whining , 'cause i wanted to spend more time with these characters-- the acting , writing , and production values are as high as , if not higher than , comparable american dramas . this father-and-son delight-- sverak also wrote the script , while his son , jan , directed-- won a golden globe for best foreign language film and , a couple days after i saw it , walked away an oscar . in czech and russian , with english subtitles . ";
}
//对文章根据分隔符进行分词,将结果保存到rawWords数组中
public void splitWord(){
//分词的时候,因为标点符号不参与,所以所有的符号全部替换为空格
final char SPACE = ' ';
content = content.replace(''', SPACE).replace(',', SPACE).replace('.', SPACE);
content = content.replace('(', SPACE).replace(')', SPACE).replace('-', SPACE);

rawWords = content.split("\s+");//凡是空格隔开的都算单词,上面替换了', 所以I've 被分成2个 //单词
}
//统计词,遍历数组
public void countWordFreq() {
//将所有出现的字符串放入唯一的set中,不用map,是因为map寻找效率太低了
Set set = new TreeSet();

for(String word: rawWords){
set.add(word);
}

Iterator ite = set.iterator();
List wordsList = new ArrayList();
List freqList = new ArrayList();
//多少个字符串未知,所以用list来保存先
while(ite.hasNext()){
String word = (String) ite.next();

int count = 0;//统计相同字符串的个数
for(String str: rawWords){
if(str.equals(word)){
count++;
}
}

wordsList.add(word);
freqList.add(count++);
}

//存入数组当中
words = wordsList.toArray(new String[0]);

wordFreqs = new int[freqList.size()];
for(int i = 0; i < freqList.size(); i++){
wordFreqs[i] = freqList.get(i);
}

}
//根据词频,将词数组和词频数组进行降序排序
public void sort() {

class Word{
private String word;
private int freq;

public Word(String word, int freq){
this.word = word;
this.freq = freq;
}
}
//注意：此处排序,1）首先按照词频降序排列, 2）如果词频相同,按照字母降序排列,
//如 'abc' > 'ab' >'aa'
class WordComparator implements Comparator{
public int compare(Object o1, Object o2) {
Word word1 = (Word) o1;
Word word2 = (Word) o2;

if(word1.freq < word2.freq){
return 1;
}else if(word1.freq > word2.freq){
return -1;
}else{

int len1 = word1.word.trim().length();
int len2 = word2.word.trim().length();

String min = len1 > len2? word2.word: word1.word;
String max = len1 > len2? word1.word: word2.word;

for(int i = 0; i < min.length(); i++){
if(min.charAt(i) < max.charAt(i)){
return 1;
}
}

return 1;

}
}

}

List wordList = new ArrayList();

for(int i = 0; i < words.length; i++){
wordList.add(new Word(words[i], wordFreqs[i]));
}

Collections.sort(wordList, new WordComparator());

for(int i = 0; i < wordList.size(); i++){
Word wor = (Word) wordList.get(i);

words[i] = wor.word;
wordFreqs[i] = wor.freq;
}

}
//将排序结果输出
public void printResult() {
System.out.println("Total " + words.length + " different words in the content!");
for(int i = 0; i < words.length; i++){
System.out.println(wordFreqs[i] + " " + words[i]);
}
}
//测试类的功能
public static void main(String[] args) {
Article a = new Article();
a.splitWord();
a.countWordFreq();
a.sort();
a.printResult();
}
}
-----------------------
Total 99 different words in the content!
5 and
4 the
4 i
4 a
3 as
2 with
2 who
2 to
2 time
2 sverak
2 son
2 s
2 old
2 of
2 it
2 in
2 his
2 czech
1 zdenek
1 year
1 wrote
1 writing
1 won
1 whining
1 while
1 wanted
1 walked
1 ve
1 values
1 though
1 this
1 these
1 that
1 than
1 taking
1 subtitles
1 spend
1 some
1 so
1 seen
1 script
1 saw
1 russian
1 richest
1 remain
1 rather
1 production
1 plays
1 oscar
1 one
1 not
1 more
1 m
1 likely
1 life
1 language
1 kolya
1 jan
1 is
1 increasingly
1 impacted
1 if
1 higher
1 high
1 he
1 golden
1 globe
1 foreign
1 for
1 five
1 finds
1 films
1 film
1 father
1 english
1 ends
1 dramas
1 directed
1 delight
1 days
1 couple
1 confirmed
1 comparable
1 characters
1 cellist
1 cause
1 care
1 by
1 boy
1 best
1 bachelor
1 away
1 are
1 an
1 american
1 also
1 after
1 acting
1 abruptly

String result = sentence.replaceAll("a","1").replaceAll("b","2").;
依此写 这个可以查API的

class Demo{
x09
x09public static void main(String[] args) {
x09x09Box box =new Box(2, 2, 2);
x09 System.out.println("这个长方体的体积是：" +box.volume());
}
x09
}
class Box {
double width;
double height;
double depth;
Box(double w,double h,double d) {
width = w;
height = h;
depth = d;
}
double volume() {
return width * height * depth;
}
}

计算器可以用的 调下模式

public class ShortTest {
public static void main(String[] args) {
Scanner s = new Scanner(System.in);
String num = s.nextLine();
int number = Integer.parseInt(num);
ShortTest.printDiagram(number);
}

public static void printDiagram(int i){
for (int le=0;le<=i;le++){
for(int j=0;jSystem.out.print('*');
for (int k=0;k System.out.print('.');
}
System.out.println();
}
}
}输入4,打出来*.*..*..*...*...*...*.*.*.*.

选A
synchronized(同步)
在Java中此关键字以两种相关的方式使用,可以作为一个修饰符,也可以作为一条语句。
首选,这是一个应用于类或实例方法的修饰符。它表示,相应方法在修改类的内部状态 (或者修改类的一个实例的内部状态)时,所用的方式不是线程安全的。 在运行一个synchronized类方法之前,Java得到该类的一个锁, 以此确保其他线程无法并发地修改此类。 在运行一个synchronized实例方法前,Java将对调用该方法的实例得到一个锁, 从而确保其他线程不能同时修改此对象。Java还支持一个synchronized语句,它相当于指定代码的一个 “临界区”。synchronized关键字后面是一个用括号括起的表达式以及一条语句或一个语句块。 此表达式必须计算为一个对象或数组。 Java在执行相应语句之前将对所指定的对象或数组得到一个锁。

The system is a multimedia demonstration which is realized by Java language under Window XP system; it's a system developed by 网络游鱼.The present multimedia demonstration features increasingly powerful technologies, which are applicable wildly and replace use of brush and paper to delineate vivid animation in the past .The ultimate mission of this system is to realize the systematization, the normalization and the automation of the various information in the process of multimedia demonstration.With application of Java multimedia, multithreading ,network communication, and other techniques, this system combines the Principle of information interaction on computer networks to present an vivid & dramatic and lively & lifelike demonstration system which is equiped with capacity of information interaction.

真有才，这种题给10分。
还是自己写吧。
说实话都是很基础的东西。
上班写这些东西也要1小时以上的。搭建一个通用的方法的话。