关于java300行代码的信息

一个java文件里面最多写多少行代码？

1，java规范中一般不建议一个java类中超过500行

2，一行的长度不超过200个

3，按照规定格式将代码格式化

相关问答

Q1: 一个java类标准代码行数范围大概是多少

以1000行为准，超过千行就要考虑类拆分了。

类的代码行数没有特定的行数限制规范。根据实际情况决定。

对于经常使用的java类，代码行数应该尽可能的少，这样能减少java类的加载时间，减少内存频繁占用和回收。如果类过大，java类加载会耗时并且占用内存大。容易引起内存回收。

Q2: 求java代码300行左右，要有注释，能运行，基础点的越基础的越好，300行以上就好，不要太长的

300行能干啥啊，你还不如自己做做练习题。

package suoha;

import java.util.ArrayList;import java.util.Random;

public class MainFunction {

private ArrayListMyCard cards = new ArrayListMyCard();

private int[] cardNumArr = new int[52];

private int[] mycards = new int[5];

private int[] p1cards = new int[5];

public static void main(String[] args) {

MainFunction mainfunc = new MainFunction();

mainfunc.makeCards();

mainfunc.cardNumArr = mainfunc.shuffleCards(mainfunc.cardNumArr);

mainfunc.catchCards();

mainfunc.showAllCardsOfHand();

//mainfunc.printNums();

}

/**

* 洗牌

* @param cardNums

* @return

*/

private int[] shuffleCards(int[] cardNums){

int size = cardNums.length;

int[] returnNums = new int[size];

//System.out.println(cardNums[0]+"=========================");

Random rand = new Random();

for(int i=size-1;i0;i--){

int nextInt = rand.nextInt(i);

returnNums[size-1-i] = cardNums[nextInt];

cardNums[nextInt] = cardNums[i];

cardNums[i] = returnNums[size-1-i];

//System.out.println("suijishu:"+nextInt+"||zhi:"+returnNums[size-1-i]);

}

returnNums[size-1] = cardNums[0];

return returnNums;

}

/**

* 抓牌

*/

private void catchCards(){

for(int i=0;i5;i++){

mycards[i] = cardNumArr[2*i];

p1cards[i] = cardNumArr[2*i+1];

}

}

private void showAllCardsOfHand(){

System.out.print("你手中的牌是：||");

for(int i=0;i5;i++){

MyCard myCard = cards.get(mycards[i]-1);

System.out.print(myCard.toString()+"||");

}

System.out.println();

System.out.print("对家手中的牌是：||");

for(int i=0;i5;i++){

MyCard myCard = cards.get(p1cards[i]-1);

System.out.print(myCard.toString()+"||");

}

}

/**

* 显示牌的顺序

*/

private void printNums(){

for(int i=0;icardNumArr.length;i++){

System.out.print(cardNumArr[i]+",");

}

}

/**

* 制作卡片

*/

private void makeCards(){

for(int i=1;i=13;i++){

for(int j=1;j=4;j++){

//System.out.println((i-1)*4+j);

MyCard card = new MyCard((i-1)*4+j, j, i);

cardNumArr[(i-1)*4+j-1] = (i-1)*4+j;

cards.add(card);

}

// MyCard card1 = new MyCard((i-1)*4+1, 1, i);

// MyCard card2 = new MyCard((i-1)*4+2, 2, i);

// MyCard card3 = new MyCard((i-1)*4+3, 3, i);

// MyCard card4 = new MyCard((i-1)*4+4, 4, i);

// cards.add(card1);

// cards.add(card2);

// cards.add(card3);

// cards.add(card4);

}

}

}

Q3: 谁帮我写一段300行左右的代码？

这个计算器可是我自己写了好几天才写好的耶，你能在网上找到？

计算器：

// Calculator.java

public class Calculator {

private static final char NO_OP = '\0';

private static final char PLUS = '+';

private static final char SUBTRACT = '-';

private static final char MULTIPLY = '*';

private static final char DIVIDE = '/';

private float number1 = 0.0F;

//private float number2 = Float.NaN;

private char operator = NO_OP;

//等于运算

public String opEquals(String number) {

float result;

if ( operator == NO_OP ) {

result = parseNumber(number);

} else {

result = performOperation(parseNumber(number));

}

operator = NO_OP;

number1 = result;

return Float.toString(result);

}

//加法运算

public String opAdd(String number) {

float result;

if ( operator == NO_OP ) {

result = parseNumber(number);

} else {

result = performOperation(parseNumber(number));

}

operator = PLUS;

number1 = result;

return Float.toString(result);

}

//减法运算

public String opSubtract(String number) {

float result;

if ( operator == NO_OP ) {

result = parseNumber(number);

} else {

result = performOperation(parseNumber(number));

}

operator = SUBTRACT;

number1 = result;

return Float.toString(result);

}

//乘法运算

public String opMultiply(String number) {

float result;

if ( operator == NO_OP ) {

result = parseNumber(number);

} else {

result = performOperation(parseNumber(number));

}

operator = MULTIPLY;

number1 = result;

return Float.toString(result);

}

//除法运算

public String opDivide(String number) {

float result;

if ( operator == NO_OP ) {

result = parseNumber(number);

} else {

result = performOperation(parseNumber(number));

}

operator = DIVIDE;

number1 = result;

return Float.toString(result);

}

//处理运算符

private float performOperation(float number2) {

float result = 0.0F;

switch ( operator ) {

case PLUS:

result = number1 + number2;

break;

case SUBTRACT:

result = number1 - number2;

break;

case MULTIPLY:

result = number1 * number2;

break;

case DIVIDE:

result = number1 / number2;

break;

}

return result;

}

//将字符串类型转换为浮点型

private static float parseNumber(String number) {

float real_number;

try {

real_number = Float.parseFloat(number);

} catch (NumberFormatException e) {

real_number = Float.NaN;

}

return real_number;

}

}

GUI程序：

// CalculatorGUI.java

import java.awt.*;

import java.awt.event.*;

public class CalculatorGUI {

// 定义按钮

private Button key0, key1, key2, key3, key4;

private Button key5, key6, key7, key8, key9;

private Button keyequal, keyplus, keyminus;

private Button keyperiod, keymult, keydiv;

// 定义存放按钮的区域

private Panel buttonArea;

// 定义存放运算结果的区域

private Label answer;

// 用来实现运算功能的类的对象实例化

private Calculator calculator;

private boolean readyForNextNumber;

public CalculatorGUI() {

calculator = new Calculator();

readyForNextNumber = true;

answer = new Label("0.0",Label.RIGHT);

key0 = new Button("0");

key1 = new Button("1");

key2 = new Button("2");

key3 = new Button("3");

key4 = new Button("4");

key5 = new Button("5");

key6 = new Button("6");

key7 = new Button("7");

key8 = new Button("8");

key9 = new Button("9");

keyequal = new Button("=");

keyplus = new Button("+");

keyminus = new Button("-");

keymult = new Button("*");

keydiv = new Button("/");

keyperiod = new Button(".");

buttonArea = new Panel();

}

public void launchFrame() {

buttonArea.setLayout(new GridLayout(4,4));

buttonArea.add(key7);

buttonArea.add(key8);

buttonArea.add(key9);

buttonArea.add(keyplus);

buttonArea.add(key4);

buttonArea.add(key5);

buttonArea.add(key6);

buttonArea.add(keyminus);

buttonArea.add(key1);

buttonArea.add(key2);

buttonArea.add(key3);

buttonArea.add(keymult);

buttonArea.add(key0);

buttonArea.add(keyperiod);

buttonArea.add(keyequal);

buttonArea.add(keydiv);

// 设置事件接收句柄

OpButtonHanlder op_handler = new OpButtonHanlder();

NumberButtonHanlder number_handler = new NumberButtonHanlder();

key0.addActionListener(number_handler);

key1.addActionListener(number_handler);

key2.addActionListener(number_handler);

key3.addActionListener(number_handler);

key4.addActionListener(number_handler);

key5.addActionListener(number_handler);

key6.addActionListener(number_handler);

key7.addActionListener(number_handler);

key8.addActionListener(number_handler);

key9.addActionListener(number_handler);

keyperiod.addActionListener(number_handler);

keyplus.addActionListener(op_handler);

keyminus.addActionListener(op_handler);

keymult.addActionListener(op_handler);

keydiv.addActionListener(op_handler);

keyequal.addActionListener(op_handler);

// 新建一个帧，并且加上消息监听

Frame f = new Frame("计算器");

f.addWindowListener(new WindowAdapter() {

public void windowClosing(WindowEvent e) {

System.exit(0);

}

});

f.setSize(200, 200);

f.add(answer, BorderLayout.NORTH);

f.add(buttonArea, BorderLayout.CENTER);

f.setVisible (true);

}

//响应按钮事件，并根据不同的按钮事件进行不同的运算

private class OpButtonHanlder implements ActionListener {

public void actionPerformed(ActionEvent event) {

char operator = event.getActionCommand().charAt(0);

String result = "";

switch ( operator ) {

case '+':

result = calculator.opAdd(answer.getText());

break;

case '-':

result = calculator.opSubtract(answer.getText());

break;

case '*':

result = calculator.opMultiply(answer.getText());

break;

case '/':

result = calculator.opDivide(answer.getText());

break;

case '=':

result = calculator.opEquals(answer.getText());

break;

}

answer.setText(result);

readyForNextNumber = true;

}

}

//处理连续运算时主界面的显示

private class NumberButtonHanlder implements ActionListener {

public void actionPerformed(ActionEvent event) {

if ( readyForNextNumber ) {

answer.setText(event.getActionCommand());

readyForNextNumber = false;

} else {

answer.setText(answer.getText() + event.getActionCommand().charAt(0));

}

}

}

//主函数，也是该应用程序的执行入口处

public static void main(String[] args) {

CalculatorGUI calcGUI = new CalculatorGUI();

calcGUI.launchFrame();

}

}

注意：运行的是GUI程序

Q4: 一个JAVA程序员一年写多少条代码

我曾经最多一天写过1500行代码，如果正常情况下，一天应该能写500行，一年不休息差不多20万行吧

Q5: java 项目 代码行数多少 算大项目

java项目的大小衡量标准：

微型：只是一个人，甚至是半日工作在几天内完成的软件；  

小型：一个人半年内完成的 2000 行以内的程序；

中型： 5 个人在 1 年多的时间内完成的 5000-50000 行的程序；

大型： 5-10 人在两年内完成的 50000-100000 行的程序；

甚大型： 100-1000 人参加用 4-5 年完成的具有 100 ， 0000 行的软件项目；

极大型： 2000-5000 人参加， 10 年内完成的 1000 万行以内的程序；

以上摘自：《软件工程概论》   郑人杰、殷人民编

这样的观点是以代码行作为计量标准的，认为代码行多的自然项目也就大了。