编程题目:
8.取出一个字符串中字母出现的次数。如:字符串:”abcdekka27qoq” ,输出格式为:a(2)b(1)k(2)…。
示例代码:
package program.string.exercise08;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;
/**
* 8.取出一个字符串中字母出现的次数。如:字符串:"abcdekka27qoq" ,
* 输出格式为:a(2)b(1)k(2)...
*
*/
public class EnglishCount {
public static void main(String[] args) {
String str = "abcdekka27qoq";
countEnglish(str);
}
private static void countEnglish(String str) {
StringBuffer sbf = new StringBuffer();
Map<Character, Integer> map = new HashMap<Character, Integer>();
char[] cs = str.toCharArray();
for(int i=0;i<cs.length;i++){
if(cs[i] >= 'a' && cs[i] <= 'z'){
if(!map.containsKey(cs[i])){
map.put(cs[i], 1);
}else{
map.put(cs[i], map.get(cs[i])+1);
}
}
}
Set<Character> keySet = map.keySet();
for(Character key : keySet){
sbf.append(key+"("+map.get(key)+")");
}
System.out.println(sbf);
}
}
结果显示: