【Java】三种方式实现统计字符串中字母，数字，空格和其它类型的数量

1、问题

2、解答

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
* 三种方式实现统计字符串中的字符，数字，空格和其它字符个数
*
*/
public class CharCountStringTest {
public static void main(String[] args) {
String s= "123abc-\t\nd n";

//根据字符统计
getCharKindByChar(s);

//根据ASCLL码统计
getCharKindByASCLLCode(s);

//根据正则统计
getCharKindByRegex();

}

//1、根据字符统计
private static void getCharKindByChar(String s){
int charCount=0,numberCout=0,blankCount=0,otherCount=0;
for (int i=0;i<s.length();i++){
//英文字母
char temp=s.charAt(i);
if (('a'<=temp&& temp<='z')||('A'<=temp&&temp<='Z')){
charCount++;
//数字类型
}else if('0'<=temp&&temp<='9'){
numberCout++;
//空格类型(不全)
}else if(temp=='\t'||temp=='\n'||temp==' '){
blankCount++;
//其它类型
}else {
otherCount++;
}
}
System.out.println("**********");
System.out.println("英文字母出现的次数："+charCount);
System.out.println("数字出现的次数："+numberCout);
System.out.println("空格字符出现的次数："+blankCount);
System.out.println("其它字符："+otherCount);
}

//2、根据ASCLL码统计
private static void getCharKindByASCLLCode(String s){
int charCount=0,numberCout=0,blankCount=0,otherCount=0;
for (int i=0;i<s.length();i++){
//英文字母
char temp=s.charAt(i);
if ((65<=temp&& temp<=90)||(97<=temp&&temp<=122)){
charCount++;
//数字类型
}else if(48<=temp&&temp<=57){
numberCout++;
//空格类型
}else if(temp<=32){
blankCount++;
//其它类型
}else {
otherCount++;
}
}
System.out.println("**********");
System.out.println("英文字母出现的次数："+charCount);
System.out.println("数字出现的次数："+numberCout);
System.out.println("空格字符出现的次数："+blankCount);
System.out.println("其它字符："+otherCount);
}

//3、根据正则表达式匹配
private static void getCharKindByRegex(){
InputStreamReader inputStreamReader = new InputStreamReader(System.in);
BufferedReader bufferedReader = new BufferedReader(inputStreamReader);
System.out.println("请输入字符串：");
String string="";

try {
string=bufferedReader.readLine();
bufferedReader.close();
} catch (IOException e) {
e.printStackTrace();
}
Pattern letterPattern = Pattern.compile("[a-zA-Z]");
Pattern numberPattern = Pattern.compile("[0-9]");
Pattern blandPattern = Pattern.compile("[\\s|\r|\n|\t]");//不全

Matcher letterMatcher = letterPattern.matcher(string);
Matcher numberMatcher = numberPattern.matcher(string);
Matcher blandMatcher = blandPattern.matcher(string);

StringBuffer stringBufferLetter = new StringBuffer();
StringBuffer stringBufferNumber = new StringBuffer();
StringBuffer stringBufferBlank = new StringBuffer();

while(letterMatcher.find()){
stringBufferLetter.append(letterMatcher.group(0));
}
while(numberMatcher.find()){
stringBufferNumber.append(numberMatcher.group(0));
}
while(blandMatcher.find()){
stringBufferBlank.append(blandMatcher.group(0));
}

int otherNumber=string.length()-stringBufferLetter.length()-stringBufferNumber.length()-stringBufferBlank.length();

System.out.println("**********");
System.out.println("字母类型："+ stringBufferLetter.length()+"个");
System.out.println("数字类型："+ stringBufferNumber.length()+"个");
System.out.println("空格类型："+ stringBufferBlank.length()+"个");
System.out.println("其它类型："+ otherNumber+"个");

}

}