Java程序检查字符是否是字母

编写一个Java程序，使用if-else语句和示例检查一个字符是否是字母。If条件检查用户输入的字符是否在a到z或A到Z之间。如果为真，则是字母；否则，则不是字母。

import java.util.Scanner;

public class CharIsAlphabet1 {
	
	private static Scanner sc;
	
	public static void main(String[] args) {
		
		char ch;
		sc= new Scanner(System.in);

		System.out.print("Please Enter any Character =  ");
		ch = sc.next().charAt(0);
		
		if((ch >= 'a' && ch <= 'z') || (ch >= 'A' && ch <= 'Z')) {
			System.out.println(ch + " is an Alphabet");
		}
		else {
			System.out.println(ch + " is Not an Alphabet");
		}
		
	}
}

检查数字

Please Enter any Character =  9
9 is Not an Alphabet

Java程序使用条件运算符检查字符是否为字母

import java.util.Scanner;

public class CharIsAlphabet2 {
	
	private static Scanner sc;
	
	public static void main(String[] args) {
		
		char ch;
		sc= new Scanner(System.in);

		System.out.print("Please Enter any Character =  ");
		ch = sc.next().charAt(0);
		
		String result = ((ch >= 'a' && ch <= 'z') || (ch >= 'A' && ch <= 'Z')) ?
				ch + " is an Alphabet" : ch + " is Not";
		
		System.out.println(result);
		
		}	
}

Please Enter any Character =  m
m is an Alphabet

Please Enter any Character =  .
. is Not

在此程序中，我们有一个isAlphabetic字符函数，用于检查给定的字符是否为字母。我们使用相同的函数。

import java.util.Scanner;

public class CharIsAlphabet3 {
	
	private static Scanner sc;
	
	public static void main(String[] args) {
		
		char ch;
		sc= new Scanner(System.in);

		System.out.print("Please Enter any Letter =  ");
		ch = sc.next().charAt(0);
		
		if(Character.isAlphabetic(ch)) {
			System.out.println(ch + " is an Alphabet");
		}
		else {
			System.out.println(ch + " is Not");
		}
		
	}
}

Please Enter any Letter =  K
K is an Alphabet

Please Enter any Letter =  *
* is Not

每个字母都与一个ASCII码相关联。这个Java示例检查给定字符的ASCII值是否在65到90（A到Z）或97到122（a到z）之间。

import java.util.Scanner;

public class CharIsAlphabet4 {
	
	private static Scanner sc;
	
	public static void main(String[] args) {
		
		char ch;
		sc= new Scanner(System.in);

		System.out.print("Please Enter any Letter =  ");
		ch = sc.next().charAt(0);
		
		if((ch >= 65 && ch <= 90) || (ch >= 97 && ch <= 122)) {
			System.out.println(ch + " is an Alphabet");
		}
		else {
			System.out.println(ch + " is Not");
		}
		
	}
}

Please Enter any Letter =  j
j is an Alphabet

Please Enter any Letter =  1
1 is Not