Java Scanner.nextDouble方法代码示例

import java.util.Scanner; //导入方法依赖的package包/类
public static void main(String[] args) {
    Scanner input = new Scanner(System.in);
    System.out.print("Enter your age in years: ");
    double age = input.nextDouble();
    System.out.print("Enter your maximum heart rate: ");
    double rate = input.nextDouble();
    double fb = (rate - age) * 0.65;
    System.out.println("Your ideal fat-burning heart rate is " + fb);
    
    System.out.print("\nPlease enter an Integer: ");
    while(!input.hasNextInt()) {
        input.nextLine();
        System.out.print("Invalid integer; please enter an integer: ");
    }
    int i = input.nextInt();
    System.out.println("Done");
}
 

import java.util.Scanner; //导入方法依赖的package包/类
/**
 * Reads the input file for data.
 *
 * @return The data matrix with raw program data.
 * @throws IOException In case there are IO problems.
 */
private static double[][] readInput() throws IOException {
    // IO-related objects and variables
    final String INPUT_FILENAME = "resources/Main_08_Input.txt"; // Input file name
    Scanner sc = new Scanner(new File(INPUT_FILENAME)); // File scanner
    int numOfNums = sc.nextInt(); // The first number in the input file
    double[][] out = new double[2][numOfNums]; // Method output data matrix

    /*
     * Reminder: double[][] out is what becomes the data matrix for the
     * whole program. It has a constant width of 2 and a variable height
     * of "length" depending on the amount of data to process in the
     * input file.
     */

    // Assign data from file to array
    for (int i = 0; i < numOfNums; i++) {
        out[0][i] = sc.nextDouble();
    }

    // Close Scanner
    sc.close();

    return out; // Output raw program data
}
 

import java.util.Scanner; //导入方法依赖的package包/类
public static void main(String[] args) {
	// entrada = 3 notas
	// Seria o prompt do java script
	Scanner sc = new Scanner(System.in);
	System.out.println("Digite o valor da nota 1:");
	double nota1 = sc.nextDouble();
	System.out.println("Digite o valor da nota 2:");
	double nota2 = sc.nextDouble();
	System.out.println("Digite o valor da nota 3:");
	double nota3 = sc.nextDouble();

	// processamento = calcular media
	double media = (nota1 + nota2 + nota3)/3;

	// saida = condicao do aluno (Reprovado, aprovado, recuperacao)
	if (media <= 5) {
		System.out.println("Reprovado");
	} else if (media > 5 && media < 7) {
		System.out.println("Recuperacao");
	} else {
		System.out.println("Aprovado");
	}
}
 

import java.util.Scanner; //导入方法依赖的package包/类
private static void testViaUserInput(Network network) {
	@SuppressWarnings("resource")
	Scanner in = new Scanner(System.in);
	
	while (true) {
		int size = network.getInputLayer().size();
		double[] input = new double[size];
		for (int i = 0; i < size; i++) {
			System.out.println("Enter Input " + (i + 1) + ": ");
			input[i] = in.nextDouble();
		}

		network.clear();
		network.setInput(input);
		network.calculate();
	
		for (int i = 0; i < network.getOutput().length; i++) {
			System.out.println("Output: " + Math.round(network.getOutput()[i]) + " [" + network.getOutput()[i] + "]");
		}
	}
}
 

import java.util.Scanner; //导入方法依赖的package包/类
public static void printAverage(Scanner sf, int N) {
  DelayLine<Double> temp = new DelayLine<Double>(N, 0.0);
  out.printf("Temperaturas hora-a-hora e média das últimas %d horas.\n", N);
  out.printf("(As primeiras %d médias não são exatas!)\n", N);
  out.printf("%3s %4s %7s %7s\n", "dia", "hora", "temp.", "média");
  int t = 0;
  while (sf.hasNextDouble()) {
    double nova = sf.nextDouble();
    // Calcula soma das últimas N horas:
    temp.in(nova);
    double somaN = 0.0;
    for (int hora = -N; hora < 0; hora++) {
      somaN += temp.get(hora);
    }
    out.printf("%3d   %02d %7.1f %7.1f\n", t/24, t%24, nova, somaN/N);
    t++;
  }
}
 

import java.util.Scanner; //导入方法依赖的package包/类
public static void main(String[] args) throws IOException{

        BufferedReader input = new BufferedReader(new InputStreamReader(System.in));
        Scanner sc = new Scanner(System.in);

        System.out.println("Initialize Bank Account: ");
        System.out.print("Input initial balance: ");
        double bal = sc.nextDouble();
        System.out.print("Input rate of interest: ");
        double rate = sc.nextDouble();
        BankAcct acc = new BankAcct(bal, rate);
        
        System.out.print("Input password to calcualte interest: ");
        String pass = input.readLine();
        
        BankAcct.Private_Methods obj = new BankAcct(bal, rate).new Private_Methods();
        
        if(pass.equals(obj.password)){
            System.out.print("Input time for interest: ");
            int time = sc.nextInt();
            obj.calculateInterest(time);
        }else
            System.out.println("Login Failed!! Wrong Password");
    }
 

import java.util.Scanner; //导入方法依赖的package包/类
public static void main(String[] args) {
    Scanner x = new Scanner(System.in);
    int n = x.nextInt();
    double r = x.nextDouble();
    double PI = Math.PI;
    double a[][] = new double[n][2];
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < 2; j++) {
            a[i][j] = x.nextDouble();
        }
    }
    double sum = 0;
    for (int i = 0; i < n - 1; i++) {
        sum += func(a[i][0], a[i + 1][0], a[i][1], a[i + 1][1]);
    }
    sum += func(a[0][0], a[n - 1][0], a[0][1], a[n - 1][1]) + 2 * PI * r;
    System.out.printf("%.2f", sum);
}
 

import java.util.Scanner; //导入方法依赖的package包/类
public static void main(String[] args) {
    Scanner input = new Scanner(System.in);
    double n;
    
    System.out.print("Valor qualquer: ");
    n = input.nextDouble();
    input.close();
    
    if (n > 0)
        System.out.println("O valor informado é positivo");
    else if (n < 0)
        System.out.println("O valor informado é negativo");
    else
        System.out.println("O valor informado é nulo");
    
}
 

import java.util.Scanner; //导入方法依赖的package包/类
public static void main(String[] args) {
	// entrada = preco de custo + percentual
	// Seria o prompt do java script
	Scanner sc = new Scanner(System.in);
	System.out.println("Digite o preco custo:");
	double precoCusto = sc.nextDouble();
	System.out.println("Digite o percentual:");
	float percentual = sc.nextFloat();

	// processamento = valor de venda
	double valorVenda = (percentual / 100 * precoCusto) + precoCusto;
	// saida = valor da venda
	// Forma de arredondar um valor 
	valorVenda = Math.round(valorVenda);
	System.out.println("Valor de venda = " + valorVenda);
}
 

import java.util.Scanner; //导入方法依赖的package包/类
public static void main(String[] args) {
    /* Save input */
    Scanner scan = new Scanner(System.in);
    int size = scan.nextInt();
    double [] X = new double[size];
    double [] Y = new double[size];
    for (int i = 0; i < size; i++) {
        X[i] = scan.nextDouble();
    }
    for (int i = 0; i < size; i++) {
        Y[i] = scan.nextDouble();
    }
    scan.close();
    
    System.out.format("%.3f", spearman(X, Y));
}
 

import java.util.Scanner; //导入方法依赖的package包/类
public static void main(String[] args) {
  Scanner scan = new Scanner(System.in);

  double lambda = scan.nextDouble();
  int k = scan.nextInt();
  scan.close();

  System.out.println(poisson(k, lambda));
}
 

import java.util.Scanner; //导入方法依赖的package包/类
/**
 * Parses a WKT point data from the intialized reader
 * @return Point data as a Coordinate
 * @throws IOException if couldn't parse coordinate values
 */
protected Coord parsePoint() throws IOException {
	String coords = readNestedContents(reader);
	Scanner s = new Scanner(coords);
	double x,y;
	
	try {
		x = s.nextDouble();
		y = s.nextDouble();
	} catch (RuntimeException e) {
		throw new IOException("Bad coordinate values: '" + coords + "'");
	}
	
	return new Coord(x,y);
}
 

import java.util.Scanner; //导入方法依赖的package包/类
public static void main(String[] args)
{
	double money;
	double consumption;	
	Scanner sc = new Scanner(System.in);
	System.out.println("请输入是否是会员(是(y)/否(n)):");
	String a = sc.next();
	if("y".equals(a))
	{
		System.out.println("请输入购物金额:");
		consumption = sc.nextDouble();
		if(consumption >= 20)
		{
			money = consumption * 0.75;
			System.out.println("实际支付:" + money);
		}
		else
		{
			money = consumption * 0.8;
			System.out.println("实际支付:" + money);
		}
	}
	else
	{
		System.out.println("请输入购物金额:");
		consumption = sc.nextDouble();
		if(consumption >= 100)
		{
			money = consumption * 0.9;
			System.out.println("实际支付:" + money);
		}
		else
		{
			money = consumption;
			System.out.println("实际支付:" + money);
		}
	}
	sc.close();
}
 

import java.util.Scanner; //导入方法依赖的package包/类
public static void main(String[]args)
{
	Scanner sc = new Scanner(System.in);
	System.out.print("圆的半径是：");
	double radius = sc.nextDouble();;
	double pi = 3.14159;
	double area = pi * radius * radius;
	System.out.println("圆的面积是：" + area);
	sc.close();
}
 

import java.util.Scanner; //导入方法依赖的package包/类
public static void main (String[]args)
{
	Scanner sc = new Scanner(System.in);
	System.out.println("请输入是否是会员：(y/n)");
	String a = sc.next();
	double money = 0;
	if(a.equals("y"))
	{
		System.out.println("请输入购物金额：");
		money = sc.nextDouble();
		if(money >= 200.0)
		{
			System.out.println("实际支付"+money*0.75);
		}
		else 
		{
			System.out.println("实际支付"+money*0.8);
		}

	}
	else 
	{
		System.out.println("请输入购物金额：");
		money = sc.nextDouble();
		if(money >= 100.0)
		{
			System.out.println("实际支付"+money*0.9);
		}	
		else 
		{
			System.out.println("实际支付"+money);
		}
		
	}
	sc.close();

	
}