计数字符串中字符出现的次数(java实现)

public class CountLettersInArray{
public static void main(String[] args){
char[] chars=createArray();
System.out.println("The lowercase letters are:");
displayArray(chars);
int[] counts=countLetters(chars);

System.out.println();
System.out.println("The occurences of each letters are");
displayCounts(counts);
}

public static char[] createArray(){
char[] chars=new char[100];

for(int i=0;i<100;i++){
chars[i]=RandomCharacter.getRandomLowerCaseLetter();
}
return chars;
}

public static void displayArray(char[] chars){
for(int i=0;i<chars.length;i++){
if((i+1)%20==0)
System.out.println(chars[i]+" ");
else
System.out.print(chars[i]+" ");
}
}

public static int[] countLetters(char[] chars){
int[] counts=new int[26];
for(int i=0;i<counts.length;i++){
counts[chars[i]-'a']++;
}
return counts;
}

public static void displayCounts(int[] counts){
for(int i=0;i<counts.length;i++){
if((i+1)%10==0)
System.out.println(counts[i]+" "+(char)(i+'a'));
else
System.out.print(counts[i]+" "+(char)(i+'a')+" ");
}
}
}