20110525 Java 練習小記

package Chapter3;


import java.io.*;
public class Sample4 {
public static void main(String args[]) throws IOException
{
System.out.println("請輸入文字字串:");
BufferedReader br = new BufferedReader( new InputStreamReader(System.in));
String str = br.readLine();
System.out.println("剛剛輸入的字串是:"+str);
}
}

package Chapter3;

import java.io.*;

public class Sample5 {

public static void main(String[] args) throws IOException {

System.out.println("請輸入一個整數");

BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

String str = br.readLine();

int num = Integer.parseInt(str);

System.out.println(num+"是您輸入的數字");

}

}

package Chapter3;

import java.io.*;

public class Sample6 {

public static void main(String[] args) throws IOException 

{

System.out.println("請輸入兩個整數.");

BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

//連續兩次輸入, 有幾次的 readLine() 就可以接受幾次的輸入

String str1 = br.readLine();

String str2 = br.readLine();

//將兩次的輸入 轉換為整數

int num1 = Integer.parseInt(str1);

int num2 = Integer.parseInt(str2);

System.out.println("第一次輸入是"+num1);

System.out.println("第二次輸入是"+num2);

}

}

package Chapter3;

import java.io.*;

public class Homework3_3 {

public static void main(String[] args) throws IOException 

{

System.out.println("你今年幾歲?");

//BufferedReader 有點忘記要記住

BufferedReader br =  new BufferedReader(new InputStreamReader(System.in));

String str = br.readLine();

//這邊忘記 Integer.parseInt 要記住

int num = Integer.parseInt(str);

System.out.println("您今年"+num+"歲");

}

}

package Chapter3;

import java.io.*;

public class Homework3_4 {

public static void main(String[] args) throws IOException 

{

System.out.println("請輸入圓周率的值?");

BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

//這邊忘記使用 br.readLine() 要加強

String str = br.readLine();

// 這邊忘記要使用 double 前面還使用 int num 的方式來指定, 

//以致後面的 Double.parseDouble 產生錯誤, 要記住

double num = Double.parseDouble(str);

System.out.println("圓周率的值是:"+num);

}

}

package Chapter3;

import java.io.*;

public class Homework3_5 {

public static void main(String[] args) throws IOException

{

System.out.println("請輸入身高和體重:");

BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

String str1 = br.readLine();

String str2 = br.readLine();

double num1 = Double.parseDouble(str1);

double num2 = Double.parseDouble(str2);

System.out.println("身高是:"+num1);

System.out.println("體重是:"+num2);

}

}