如何获取字符串并输出多少:空格,大写,小写等

Question

所以我希望能够获取一个字符串并输出以下内容:大写,小写,数字,句点,逗号,空格和其他符号.我已完成大部分代码,但我在该区域评论说我遇到了麻烦.我不能怎么做,而且它让我在一周的大部分时间里都难过!非常感谢任何帮助!

import java.util.*;

public class JavaPractice
{

    public static void main(String[] args) 
    {

        //declarations

        Scanner keyboard = new Scanner(System.in);
        char tryAgain = 'n';
        char linechar = ' ';
        String lineText;
        int uppercase = 0;
        int lowercase = 0;
        int digits = 0;
        int periods = 0;
        int commas = 0;
        int blanks = 0;
        int others = 0;


       do
       {
          // initialize categories       
          uppercase = 0;
          lowercase = 0;
          digits = 0;
          periods = 0;
          commas = 0;
          blanks = 0;
          others = 0;

          // user input 
          System.out.println("Enter a line of text:");
          lineText = keyboard.nextLine();

          // This is where I would like to count the number of spaces, uppercase ETC where I am having the most trouble


          // print output    

          System.out.println("Uppercase:") + (uppercase);

          System.out.println("Lowercase:") + (lowercase);

          System.out.println("Digits:") + (digits)

          System.out.println("Periods:") + (periods);

          System.out.println("Commas:") + (commas);

          System.out.println("Blanks:") + (blanks);

          System.out.println("Other Symbols":) + (others);

          // try again        

          System.out.println("Would you like to try again y/n?");

          tryAgain = keyboard.nextLine().charAt(0);

        } while (tryAgain == 'y' || tryAgain == 'Y'); //end while loop

        System.out.println("GoodBye");

    } //end main()
} //end JavaPractice

Answer 1

• 首先将转换String为char数组,请参阅String#toCharArray.您也可以使用String#charAt,toCharArray将更容易迭代字符.
• 创建一个数组的for-loop循环char.
• 对于每个char使用,Character#isWhiteSpace,Character#isLowerCase,Character#isUpperCase,Character#isDigit,Character#isLetter或与任何其他比较一下char,你需要寻找.这将涉及某种if-else声明