【2019.07.04】java 统计每个字符出现的次数

男娘i 2021-12-15 05:07 232阅读 0赞

# 统计每个字符出现的次数 #

1.  随机生成100个小写字符并将其放入一个字符数组中
2.  对数组中每个字母出现的次数进行计数：创建一个具有26个int值得数组counts，每个值存放每个字母出现的次数。

package com.ybs.practice;
    /** * @Description 类描述： * @ClassName 类名称： * @author yb.w * @version 创建时间：2019年7月4日 下午2:14:00 */
    public class CountLettersInArray { 
    	public static void main(String[] args) { 
    		// Declare and create an array
    		char[] chars = createArray();
    		
    		// Display the array
    		displayArray(chars);
    		
    		// Count the occurrences of each letter
    		int[] counts = countLetters(chars);
    		
    		// Display counts
    		System.out.println("The occurrences of each letter are:");
    		displayCounts(counts);
    	}
    	
    	private static char[] createArray() { 
    		char[] chars = new char[100];
    		
    		for(int i = 0; i < chars.length; i++)
    			chars[i] = getRandomLowerCaseLetter();
    		
    		return chars;
    	}
    	
    	private static void displayArray(char[] chars) { 
    		// Display the characters in the array 20 on each line
    		for (int i = 0; i < chars.length; i++) { 
    			if((i+1) % 20 == 0)
    				System.out.println(chars[i]);
    			else
    				System.out.print(chars[i] + " ");
    		}
    	}
    	
    	private static int[] countLetters(char[] chars) { 
    		int[] counts = new int[26];
    		
    		for(int i = 0; i < chars.length; i++) { 
    			counts[chars[i] - 'a']++; // 'b' - 'a' = 1
    		}
    		return counts;
    	}
    	
    	private static void displayCounts(int[] counts) { 
    		for(int i = 0; i < counts.length; i++) { 
    			if((i+1)%10 == 0)
    				System.out.println((char)(i + 'a') + ":" + counts[i]);
    			else
    				System.out.print((char)(i + 'a') + ":" + counts[i] + " ");
    
    		}
    	}
    	
    	public static char getRandomCharacter(char ch1, char ch2) { 
    		return (char)(ch1 + Math.random() * (ch2 - ch1 + 1));
    	}
    
    	public static char getRandomLowerCaseLetter() { 
    		return getRandomCharacter('a', 'z');
    	}
    }

# 结果 #

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM4NTM0MTA3_size_16_color_FFFFFF_t_70]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM4NTM0MTA3_size_16_color_FFFFFF_t_70]: /images/20211214/dab7bc1f4af84a7782264b25128a317a.png