令牌「<=」的語法錯誤，刪除此令牌

Question

我正在創建一個颶風規模的程序，它給我帶來了問題。所有錯誤都發生在else行。幫助將不勝感激。下面的代碼：

import java.util.Scanner; 

public class hurricaneScale { 
    public static void main(String[]args) { 
    Scanner in = new Scanner(System.in); 
    System.out.print("Please enter the wind speed (in mph):"); 
    double windSpeed = in.nextln(); 

    if (windSpeed < 39) { 
     System.out.print("  Category   Wind Speed Storm Surge Damage Potential"); 
     System.out.println("Tropical Depression < 39 mph   -   Minimal "); 
    } 
    else if (windSpeed >= 39 && <=73) { 
     System.out.print(" Category   Wind Speed Storm Surge Damage Potential"); 
     System.out.println("Tropical Storm  39 - 73 mph  -   Minimal "); 
    } 
    else if (windSpeed >= 74 && <=95) { 
     System.out.print(" Category    Wind Speed Storm Surge Damage Potential"); 
     System.out.println("Hurricane 1   74 - 95 mph 4.0' - 5.0' Minimal to extensive"); 
    } 
    else if (windSpeed >= 96 && <=110) { 
     System.out.print(" Category   Wind Speed Storm Surge Damage Potential"); 
     System.out.println("Hurricane 2  96 - 110 mph 6.0' - 8.0'  Moderate "); 
    } 
    else if (windSpeed >= 111 && <=130) { 
     System.out.print(" Category   Wind Speed  Storm Surge Damage Potential"); 
     System.out.println("Hurricane 3  111 - 130 mph  9.0' - 12.0'  Extensive "); 
    } 
    else if (windSpeed >= 131 && <=155) { 
     System.out.print(" Category   Wind Speed  Storm Surge  Damage Potential"); 
     System.out.println("Hurricane 4  131 - 155 mph 13.0' - 16.0'   Extreme "); 
    } 
    else if (windSpeed > 155) { 
     System.out.print(" Category  Wind Speed  Storm Surge  Damage Potential"); 
     System.out.println("Hurricane 5  > 155 mph   > 18.0'   Catastrophic "); 
    } 
    } 
} 

Answer 1

以下語法是無效的：

else if (windSpeed >= 39 && <=73) 

您需要更換此：

else if (windSpeed >= 39 && windSpeed <=73) 

你將不得不爲每一次出現這樣做。

Answer 2

您需要的是將windSpeed變量添加到所有if條件中。像這樣

windSpeed >= 39 && windSpeed <=73 

你不能寫windspeed >= 39 && <=73，這是不正確的。

Answer 3

windSpeed >= 39 && windSpeed <=73