Java 程序：统计字符串中的字母、数字和特殊字符

编写一个 Java 程序，使用示例统计字符串中的字母、数字和特殊字符。在此 Java 统计数字、字母和字符串中特殊字符的示例中，我们首先使用 for 循环来迭代 aldisp_str。在循环中，为了保持代码简单，我们将每个字符分配给 ch (ch = aldisp_str.charAt(i))。接下来，我们使用了 Else If 语句。

在第一个 if 条件 (ch >= ‘a’ && ch <= ‘z’ || ch >= ‘A’ && ch <= ‘Z’) 中，我们检查字符是否是字母。如果为真，则增加 alph 的值。在 else if 语句中，我们使用 (ch >= ‘0’ && ch <= ‘9’) 来检查字符是否是数字，如果为真，则增加 digit 的值。否则，增加 special character 的值。

import java.util.Scanner;

public class CountAlpDigiSpl1 {
	private static Scanner sc;
	public static void main(String[] args) {
		String aldisp_str;
		int i, alph, digi, spl;
		alph = digi = spl = 0;
		char ch;
		
		sc= new Scanner(System.in);
		System.out.print("\nPlease Enter Alpha Numeric Special String =  ");
		aldisp_str = sc.nextLine();
		
		for(i = 0; i < aldisp_str.length(); i++)
		{
			ch = aldisp_str.charAt(i);
			if(ch >= 'a' && ch <= 'z' || ch >= 'A' && ch <= 'Z' ) {
				alph++;
			}
			else if(ch >= '0' && ch <= '9') {
				digi++;
			}
			else {
				spl++;
			}
		}		
		System.out.println("\nNumber of Alphabet Characters  =  " + alph);
		System.out.println("Number of Digit Characters     =  " + digi);
		System.out.println("Number of Special Characters   =  " + spl);
	}
}

使用 While 循环的 Java 程序：统计字符串中的字母、数字和特殊字符

import java.util.Scanner;

public class CountAlpDigiSpl2 {
	private static Scanner sc;
	public static void main(String[] args) {
		String aldisp_str;
		int i, alph, digi, spl;
		i = alph = digi = spl = 0;
		char ch;
		
		sc= new Scanner(System.in);

		System.out.print("\nPlease Enter Alpha Numeric Special String =  ");
		aldisp_str = sc.nextLine();
		
		while(i < aldisp_str.length())
		{
			ch = aldisp_str.charAt(i);
			if(ch >= 'a' && ch <= 'z' || ch >= 'A' && ch <= 'Z' ) {
				alph++;
			}
			else if(ch >= '0' && ch <= '9') {
				digi++;
			}
			else {
				spl++;
			}
			i++;
		}		
		System.out.println("\nNumber of Alphabet Characters  =  " + alph);
		System.out.println("Number of Digit Characters     =  " + digi);
		System.out.println("Number of Special Characters   =  " + spl);
	}
}

Please Enter Alpha Numeric Special String =  9In12&*belo 33j^%&*(?hi

Number of Alphabet Characters  =  9
Number of Digit Characters     =  5
Number of Special Characters   =  9

在此 Java 统计数字、字母和字符串中特殊字符的示例中，我们比较的是 ASCII 值，而不是比较字符。

import java.util.Scanner;

public class CountAlpDigiSpl3 {
	private static Scanner sc;
	public static void main(String[] args) {
		String aldisp_str;
		int i, alph, digi, spl;
		i = alph = digi = spl = 0;
		int asci;
		
		sc= new Scanner(System.in);

		System.out.print("\nPlease Enter Alpha Numeric Special String =  ");
		aldisp_str = sc.nextLine();
		
		for(i = 0; i < aldisp_str.length(); i++)
		{
			asci = aldisp_str.codePointAt(i);
			if(asci >= 48 && asci <= 57 ) {
				digi++;
			}
			else if(asci >= 65 && asci <= 90 || asci >= 97 && asci <= 122)  {
				alph++;
			}
			else {
				spl++;
			}
		}		
		System.out.println("\nNumber of Alphabet Characters  =  " + alph);
		System.out.println("Number of Digit Characters     =  " + digi);
		System.out.println("Number of Special Characters   =  " + spl);
	}
}

Please Enter Alpha Numeric Special String =  Ja@#va2020!world2.0

Number of Alphabet Characters  =  9
Number of Digit Characters     =  6
Number of Special Characters   =  4

在 Java 中，我们有一个内置函数 isdigit (Character.isDigit(ch)) 来检查字符是否是数字。isAlphabetic 函数 (Character.isAlphabetic(ch)) 用于检查字符是否是字母。如果这两个条件都为假，那么该字符就是特殊字符。

import java.util.Scanner;

public class CountAlpDigiSpl4 {
	private static Scanner sc;
	public static void main(String[] args) {
		String aldisp_str;
		int i, alph, digi, spl;
		alph = digi = spl = 0;
		char ch;
		
		sc= new Scanner(System.in);

		System.out.print("\nPlease Enter Alpha Numeric Special String =  ");
		aldisp_str = sc.nextLine();
		
		for(i = 0; i < aldisp_str.length(); i++)
		{
			ch = aldisp_str.charAt(i);
			if(Character.isDigit(ch)) {
				digi++;
			}
			else if(Character.isAlphabetic(ch))  {
				alph++;
			}
			else {
				spl++;
			}
		}		
		System.out.println("\nNumber of Alphabet Characters  =  " + alph);
		System.out.println("Number of Digit Characters     =  " + digi);
		System.out.println("Number of Special Characters   =  " + spl);
	}
}

Please Enter Alpha Numeric Special String =  !@34*(Monday0?

Number of Alphabet Characters  =  6
Number of Digit Characters     =  3
Number of Special Characters   =  5

这个 Java 代码 用于统计字符串中的字母、数字和特殊字符，与上面相同。这里，我们使用 Java 函数分离了字母、数字和特殊字符的逻辑。

import java.util.Scanner;

public class CountAlpDigiSpl5 {
	private static Scanner sc;
	public static void main(String[] args) {
		String aldisp_str;
		
		sc= new Scanner(System.in);

		System.out.print("\nPlease Enter Alpha Numeric Special String =  ");
		aldisp_str = sc.nextLine();
		
		CountDigitsAlphabetsSpecials(aldisp_str);
	}
	public static void CountDigitsAlphabetsSpecials(String aldisp_str) {
		char ch;
		int alph, digi, spl;
		alph = digi = spl = 0;
		
		for(int i = 0; i < aldisp_str.length(); i++)
		{
			ch = aldisp_str.charAt(i);
			if(Character.isDigit(ch)) {
				digi++;
			}
			else if(Character.isAlphabetic(ch))  {
				alph++;
			}
			else {
				spl++;
			}
		}		
		System.out.println("\nNumber of Alphabet Characters  =  " + alph);
		System.out.println("Number of Digit Characters     =  " + digi);
		System.out.println("Number of Special Characters   =  " + spl);
	}
}

Please Enter Alpha Numeric Special String =  Sep14<>?temb@r

Number of Alphabet Characters  =  8
Number of Digit Characters     =  2
Number of Special Characters   =  4