Question

每当我输入我的句子时，它会在每次循环时打印出结果。我假设我必须把打印线放在循环外面？

import java.util.*;
public class homework4{
public static void main(String[] args) {
//Scanner
Scanner keyBd = new Scanner(System.in);
System.out.println("Enter a sentence ");
String userIn = keyBd.nextLine();
  int count = 0;
  String empty= "";

  //Code
    for (int i = 0; i < userIn.length(); i++) {
           char ch = userIn.charAt(i);

        if (ch == 'a' || ch == 'e' || ch == 'i' || ch == 'o' || ch == 'u' || ch == 'A' || ch == 'E' || ch == 'I' || ch == 'O' || ch == 'U') {
            count++;

                     System.out.println("There are " + count + " vowels in this string");

    }        
        if (ch == 'a' || ch == 'e' || ch == 'i' || ch == 'o' || ch == 'u' || ch == 'A' || ch == 'E' || ch == 'I' || ch == 'O' || ch == 'U') {
            count++;
            empty += ch + " ";

                     System.out.println("The vowels are: " + empty);

    }
    }

    }
    }

Answer 1

matrix

无需检查条件两次。当您在循环中更新变量（import java.util.*; public class homework4{ public static void main(String[] args) { //Scanner Scanner keyBd = new Scanner(System.in); System.out.println("Enter a sentence "); String userIn = keyBd.nextLine(); int count = 0; String empty= ""; //Code for (int i = 0; i < userIn.length(); i++) { char ch = userIn.charAt(i); if (ch == 'a' || ch == 'e' || ch == 'i' || ch == 'o' || ch == 'u' || ch == 'A' || ch == 'E' || ch == 'I' || ch == 'O' || ch == 'U') { count++; empty += ch + " "; } } System.out.println("There are " + count + " vowels in this string"); System.out.println("The vowels are: " + empty); } }＆amp; count）时，必须在退出循环后只打印一次。

Answer 2

您不需要两次测试元音吗？（并且只添加count两次），只有一次： -

 if (ch == 'a' || ch == 'e' || ch == 'i' || ch == 'o' || ch == 'u' || ch == 'A' || ch == 'E' || ch == 'I' || ch == 'O' || ch == 'U'){
    count++;
    empty += ch + " ";
 }

每次找到元音时，您的打印声明都不需要发生： -

for (int i = 0; i < userIn.length(); i++) {
 // not in here
}
System.out.println("There are " + count + " vowels in this string\n" + "The vowels are: " + empty);

<强>另外...

如果这里的陈述很丑陋，那里有很多条件。交换机更容易阅读，效率更高： -

 switch (ch){
   case 'a': case 'A':
   case 'e': case 'E':
   case 'i': case 'I':
   case 'o': case 'O':
   case 'u': case 'U':
     count++;
     empty += ch + " ";
     break;
 }

或将整个条件移动到方法

public boolean isVowel(char c){
  return (ch == 'a' || ch == 'e' || ch == 'i' || ch == 'o' || ch == 'u' || ch == 'A' || ch == 'E' || ch == 'I' || ch == 'O' || ch == 'U');
}

并使用

if (isVowel(ch)){
 //...
}

Answer 3

你只需要将print语句移到外面，如果计数仍然为零则设置检查条件，则表示没有元音，如果count不为零，则可以打印它。

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    android:id="@id/img"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:adjustViewBounds="true"
    android:scaleType="fitCenter" />

}

我如何打印元音和它们是什么？

3 个答案: