Question

import java.util.Scanner;

公共类方法{

/*
 * Compound interest Program Quarterly
 */


    public static void main(String[] args) {
        Scanner keyboard = new Scanner  (System.in);

        System.out.println("What is the Rate");
        int rate = keyboard.nextInt()/100;
        System.out.println("What is the Amount");
        int amount = keyboard.nextInt();
        System.out.println("How many years?");
        int years = keyboard.nextInt();

        keyboard.nextLine();
        System.out.println("How is it compounded? Press Q = Quarterly, A = Anually, S = SemiAnnualy, M = Monthly");

        String answer = keyboard.nextLine();

       int easy = amount*(1+(rate/years));
       int pow = 4 * years;


        if (answer == "/Q"){
            System.out.println("Your answer compounded Quarterly is: "  + Math.pow(easy,pow));

这是代码，但if语句带有String ==＆＃34; Q＆＃34;没有工作，因为当我按Q时没有任何事情发生？问题是什么？

Answer 1

Java对吗？使用equalsIgnoreCase是因为你可以输入＆＃39; q＆＃39;那个/他们也告诉过你，记住它

Answer 2

第一个问题是你在这一行中有一个拼写错误（正斜杠）：

if (answer == "/Q"){

第二个问题是你不能比较这样的字符串。而是使用＆＃34; equals（）＆＃34;方法

if(answer.equals("Q")){

有关详细信息，请参阅此处：How do I compare strings in Java?

Answer 3

也许你可以试试

if(answer.equals("Q"))

为什么这个If语句不能用于字符串？

3 个答案: