Java 程序查找字符串中字符的所有出现次数

编写一个 Java 程序，通过示例查找字符串中字符的所有出现次数。在此 java return all Character Occurrences 示例中，我们使用 While 循环从头到尾迭代 facStr。在其中，我们使用 String charAt (facStr.charAt(i)) 函数读取每个索引位置的字符。

接下来，我们将 acStr.charAt(i) 字符与 ch 字符进行比较，以检查它们是否相等。如果为真，我们将打印该字符及其位置（不是索引位置）。如果您想要提取索引位置，请将 i + 1 替换为 i。

import java.util.Scanner;

public class FindAllCharOccurence1 {
	private static Scanner sc;
	public static void main(String[] args) {
		String facStr;
		char ch;
		int i = 0;
		
		sc= new Scanner(System.in);

		System.out.print("\nPlease Enter any String =  ");
		facStr = sc.nextLine();
		
		System.out.print("\nEnter the Character to Find =  ");
		ch = sc.next().charAt(0);
		
		while(i < facStr.length())
		{
			if(facStr.charAt(i) ==  ch) {
				System.out.format("\n %c Found at Position %d ", ch, i + 1);
			}
			i++;
		}
	}
}

Java 字符串中所有字符出现次数的输出

Please Enter any String =  hello world

Enter the Character to Find =  l

 l Found at Position 3 
 l Found at Position 4 
 l Found at Position 10

使用 For 循环查找字符串中字符所有出现次数的 Java 程序

import java.util.Scanner;

public class FindAllCharOccurence2 {
	private static Scanner sc;
	public static void main(String[] args) {
		String facStr;
		char ch;

		sc= new Scanner(System.in);

		System.out.print("\nPlease Enter any String =  ");
		facStr = sc.nextLine();
		
		System.out.print("\nEnter the Character to Find =  ");
		ch = sc.next().charAt(0);
		
		for(int i = 0; i < facStr.length(); i++)
		{
			if(facStr.charAt(i) ==  ch) {
				System.out.format("\n %c Found at Position %d ", ch, i );
			}
		}
	}
}

Java Program to Find All Occurrences of a Character in a String

这是另一个 Java 示例，用于返回给定字符串中所有字符的出现次数。在这里，我们使用 Java 函数分离了逻辑。

import java.util.Scanner;

public class FindAllCharOccurence3 {
	private static Scanner sc;
	public static void main(String[] args) {
		String facStr;
		char ch;

		sc= new Scanner(System.in);

		System.out.print("\nPlease Enter any String =  ");
		facStr = sc.nextLine();
		
		System.out.print("\nEnter the Character to Find =  ");
		ch = sc.next().charAt(0);
		
		FindAllCharacterOccurences(facStr, ch);	
	}
	
	public static void FindAllCharacterOccurences(String facStr, char ch) {
		for(int i = 0; i < facStr.length(); i++)
		{
			if(facStr.charAt(i) ==  ch) {
				System.out.format("\n %c Found at Position %d ", ch, i);
			}
		}
	}
}

Please Enter any String =  java programming language

Enter the Character to Find =  a

 a Found at Position 1 
 a Found at Position 3 
 a Found at Position 10 
 a Found at Position 18 
 a Found at Position 22

请参考以下字符串程序。