我需要检查一个数字是否等于、2x、3x、4x、5x 大于另一个。我怎样才能做到这一点？

Question

基本上我只需要这个程序告诉我如果 a>b 和多少。所以我需要检查的条件是 if a==b, a>b,bb||a/b 的第一个条件下运行不快0)

import java.util.Scanner;

公共类主{

public static void main(String[] args) {



    Scanner input =new Scanner(System.in);

    System.out.println("what is the value for a");
    double a =input.nextDouble();
    System.out.println("what is the value for b");
    double b =input.nextDouble();


    if (a==b){
        System.out.println("a is equal to b");
    }
    else if (a>b||a/b<1||a/b>0){
        System.out.println("a is slightly bigger than b");

    }
    else if (a>b||a/b<3||a/b>=2) {
        System.out.println("a is 2x bigger than b");
    }
    else if (a>b||a/b<4||a/b>=3) {
        System.out.println("a is 3x bigger than b");
    }
    else if (a>b||a/b<5||a/b>=4) {
        System.out.println("a is 4x bigger than b");
    }

    else if (a>b||a/b<6||a/b>=5) {
        System.out.println("a is 5x bigger than b");
    }

    else if (a>b||a/b<100||a/b>6){
        System.out.println("a is alot bigger than b");
    }
    // to check if b is bigger than a
    else if (a<b||b/a<1||b/a>0){
        System.out.println("b is slightly bigger than a");

    }
    else if (a<b||b/a<3||b/a>=2) {
        System.out.println("b is 2x bigger than a");
    }
    else if (a<b||b/a<4||b/a>=3) {
        System.out.println("b is 3x bigger than a");
    }
    else if (a<b||b/a<5||b/a>=4) {
        System.out.println("b is 4x bigger than a");
    }

    else if (a<b||b/a<6||b/a>=5) {
        System.out.println("b is 5x bigger than a");
    }

// 检查它是否更大

    else if (a>b||a/b<100||a/b>6){
        System.out.println("a is alot bigger than b");



    }



}}

Answer 1

如果 a 大于 b，则第二个条件始终为真，即使 a “比 b 大很多”。你确定你不想要 && 而不是 ||到处都是？

另外，考虑添加另一个类似这样的 if 语句（以减少语句中的规则数量并提高可读性）：

if (a == b) {
  // Code
} else if (a > b) {
  // If statements when a > b
} else {
  // If statements when b > a
}

这是一个可以作为替代方案的解决方案：

public class Test {
  public static void main(String[] args) {
    Scanner input = new Scanner(System.in);
    System.out.print("a: ");
    double a = input.nextDouble();
    System.out.print("b: ");
    double b = input.nextDouble();

    double greaterInt = (a > b) ? a : b;
    double smallerInt = (a > b) ? b : a;
    char greaterChar = (a > b) ? 'a' : 'b';
    char smallerChar = (a > b) ? 'b' : 'a';

    double frac = greaterInt / smallerInt;
    boolean noRemainder = 0 == greaterInt % smallerInt;

    String msg = "";

    if (noRemainder && frac <= 5) {
      if (frac == 1)
        msg = greaterChar + " and " + smallerChar + " are equal";
      else
        msg = greaterChar + " is " + (int) frac + "x bigger than " + smallerChar;
    } else if (frac < 2) {
      msg = greaterChar + " is slightly bigger than " + smallerChar;
    } else if (frac > 5) {
      msg = greaterChar + " is a lot bigger than " + smallerChar;
    } else {
      msg = "Nothing special to say about these numbers";
    }

    System.out.println(msg);
  }
}