IvanKao的部落格

TQC+ Java

這邊先附上一些我覺得比較需要記憶的程式碼

// Integer.parseInt(String s)  將字串解析為十進位整數
// String.length() 取得字串長度
//string.equals(x) 比較字串與x是否相同
//string.substring(x,y) 取出字串中 第 x 到第 y　個字元的字串
//string.substring(x) 　取出字串中 第 x 個字元之後的字串
//用(-1)停止加總回圈：先計數在讀取，避免算到-1
//char q = keyboard.next().charAt(0);  //char為字串型態 ，讀取字串的第0項內容

103

import java.util.Scanner;

public class JPA01 {
    public static void main (String args[]){
        Scanner k = new Scanner(System.in);
        System.out.print("Please input:");
        int a = k.nextInt();
        int b = k.nextInt();
        int c = k.nextInt();
        double average = (a + b + c)/3.0;
        System.out.printf("Average: %.2f\n", average);
        
    }

}

104

import java.util.*;
public class JPA01 {
    public static void main (String args[]){
        Scanner k = new Scanner(System.in);
        System.out.print("請輸入第1組的x和y座標：");
        double x1 = k.nextDouble();
        double y1 = k.nextDouble();
        System.out.print("請輸入第2組的x和y座標：");
        double x2 = k.nextDouble();
        double y2 = k.nextDouble();
        double ans = Math.sqrt((Math.pow(x1-x2,2)+Math.pow(y1-y2,2)));
        System.out.printf("介於(%.2f,%.2f)和(%.2f,%.2f)之間的距離是%.2f\n",x1,y1,x2,y2,ans);
        
    }




}

105

import java.util.Scanner;
public class JPA01 {
    public static void main(String[] args){
        System.out.printf("請輸入您的姓名:");
        Scanner keyboard = new Scanner(System.in);
        String name = keyboard.next();  //字串要用String型態
        System.out.printf("Hi,%s 請輸入您的銅板個數:\n",name); //這邊要換行
        System.out.print("請輸入1元的數量:");
        int one = keyboard.nextInt();
        System.out.print("請輸入5元的數量:");
        int five = keyboard.nextInt();
        System.out.print("請輸入10元的數量:");
        int ten = keyboard.nextInt();
        System.out.print("請輸入50元的數量:");
        int fifty = keyboard.nextInt();
        int total = one + five*5 + ten*10 + fifty*50;
        int g1 = total % 10;
        int g10 = (total/10) % 10;  //算出每個位數的值
        int g100 = (total/100) % 10;
        int g1000 = (total/1000) % 10;
        System.out.printf("你的錢總共有:%d 千 %d 百 %d 十 %d 元",g1000,g100,g10,g1);



    }
}

106

public class JPA01 {
    public static void main(String[] args){
        double x;
        x = -3.2;
        System.out.printf("f(%.1f) = %4.4f\n",x,f(x));  //printf 格式化輸出
        x = -2.1;
        System.out.printf("f(%.1f) = %4.4f\n",x,f(x));
        x = 0;
        System.out.printf("f(%.1f) = %4.4f\n",x,f(x));
        x = 2.1;
        System.out.printf("f(%.1f) = %4.4f\n",x,f(x));


    }
    static double f(double y)   //建立一個類別，回傳f(x)的值
    {
    return 3.0 * Math.pow(y, 3) + y*2.0 - 1.0;
    }

107

public class JPA01 {
    public static void main(String argv[]) {
        int action = 1, skill = 2, teamgame = 3;

        System.out.println("The basketball grade is " + Basketball.calGrade(action,skill,teamgame));
        System.out.println("The baseball grade is " + Baseball.calGrade(skill,teamgame));  //棒球這邊只要兩個參數
    }
}

class Basketball {
    static int calGrade(int a,int s,int t)   {  //建立類別，並宣告型態
        return a + s + t;
    }
}

class Baseball {
    static int calGrade(int s,int t)   {  
        return 10 + s + t;
    }
}

108

class JPA01 {
  
  public static void main (String[] args) {
    int i = add(2, 3);  //代入int型態的類別，得到返回值
    double d = add(5.2, 4.3);  //代入double型態的類別，得到返回值
    String s = add("I love ", "Java!!");  //代入String型態的類別，得到返回值
    System.out.printf("%d %f %s %n", i, d, s); //將三個返回值代入，%n為換行
  }
  public static int add(int a,int b){          //建立int類別
  System.out.printf("Adding two integers:%d,%d\n",a,b); //換行
  return (a+b);    //返回值
  }
  public static double add(double a,double b){ //建立double類別
  System.out.printf("Adding two doubles:%.1f,%.1f\n",a,b);
  return (a+b);   //返回值
  }
  public static String add(String a,String b){ //建立String類別
  System.out.printf("Adding two strings: %s,%s\n",a,b);
  return (a+b);   //返回值
  }
}

109

public class JPA01 { 
  
    public static int adder (int x, int y, int z) {  //adder這個類別進行數值加總
        return x + y + z;                                    
    } 
   
    public static int gameRating (int s, int a, int e) { //gameRating這個類別負責呼叫adder
        return adder(s,a,e);                                      
    } 
  
    public static void main (String argv[]) { 
        int skill = 6, action = 9, excitment = 8, result; 
        result = gameRating(skill, action, excitment); 
        System.out.print("The rating of the game is "); 
        System.out.println(result);                        
    } 
} 

110

import java.util.Scanner;
public class JPA01 {
    public static void main(String args[]) {
        double totalarea;
        System.out.printf("圓形面積為：%f \n",calCircle(5));
        System.out.printf("三角形面積為：%f \n",calTriangle(10,5)); //使用%f格式，所以後面的函式要用double宣告
        System.out.printf("方形面積為：%f \n",calRectangle(5,10)); //使用%f格式，所以後面的函式要用double宣告
        totalarea = calCircle(5) + calTriangle(10,5) + calRectangle(5,10); //三個面積相加
        System.out.printf("此圖形面積為：%f \n",totalarea);
    }
    static double calCircle(double x) {
        return x * x * 3.1415926;
        
    }
    static double calTriangle(double a , double b) {
        return (a * b) / 2;
        
    }
    static double calRectangle(double a , double b) {
        return a * b;
    }
}